Darn – busted!
On a more serious note, I have not stayed there but hear that the Inn at Abeja is quite nice. We have stayed at Walla Faces Inn downtown, which was great – and they have vineyard locations as well – but a quick google search suggests they are no longer in business (??). Others may know more – and might have better recommendations.
Walla Walla is a short flight from Seattle, about an hour and a lot of fun, you can fly either to Pasco which is 45 minutes from Walla Walla or to Walla Walla direct. I highly suggest https://marcuswhitmanhotel.com/ which is an minute from the main St, where all the best restaurants and many wineries tasting rooms are. End of April would be the perfect time to visit, march might be still cold.
Inn at Abeja is gorgeous, actually the whole place, along with Mill Creek, is my favorite but it’s a 15 minutes from the center of the city where the best dining and most of the tasting rooms are. Staying in the center of the city gives you independence which is kind of nice as you can walk back to hotel and not wait for Uber.
Most of the Vineyards are across the border, in Oregon, just outside the town called Milton-Freewater, which is not know for hospitality or fine dining, staying in Walla Walla is what I would recommend.
This is a bit of an overstatement. Many vineyards are on the washington side not in the “Rocks” district. However there are not many hotels or inns actually in the vineyard. The one I know of appears to be liquidating (johnson ridge, used to be another name). Abeja is an approximate experience, but Like others, I tend to stay downtown.
Actually there are a lot of vineyards just south of Walla Walla and north of the Oregon border. I am not sure though if there are nice places to stay there (though I suspect they are).
Leo is right about the fifteen minutes – it may not sound like a lot, but if you are driving yourself the roads can be pretty dark. And I don’t know how easy it is to get an uber. Having said all that, it really depends on the type of experience you want. If you want to be out by the vineyards, then something like Abeja may work. If you want to be in town, then Marcus Whitman is nice (though I will say when I stayed there a long time ago I found the rooms fine, nothing special). The location, however, is great as mentioned – you really can walk to dozens of tasting rooms and all of the nice downtown restaurants. So again it depends on what sort of experience you are seeking.
While the Rocks district and Sevein/Seven Hills are located on the Oregon side near Milton Freewater, the majority of the vineyards are still, in fact, on the Washington side and many are a short drive from town. There are several options if you want to stay somewhere with vineyard views and a number of them are listed here (which for purposes of disclosure includes our own rental):
Uber/Lyft are starting to be more readily available for transportation and there are many available options if you want to hire a driver for the day. That said, staying in or near downtown is great as well and gives you the ability to walk to the many restaurants and tasting rooms located there. There are a number of new hotel projects in the works for downtown, but the best options for now are the Marcus Whitman or one of the many VRBO’s in the area.
What’s new in hotel world Matt? We are tiring of the MW.
It used to be that the only place to eat was a casino on an Indian reservation in Oregon. I went there about 1995 with people from Canoe Ridge, John Abbott, Larry Brooks, and the Mckibbens. Mrs. McKibben had ordered baked potato and got fries. When she pointed this out to the waitress, the waitress responded, 'Whatever…"
The Marcus Whitman is worth staying at once just for the lobby, which is something out of a grander era.
I disagree with the Marcus Whitman recommendation if being evaluated for the accommodations alone. The location can’t be beat. However, we stayed there last fall and our room was just tired, dingy, and old-fashioned. It’s not bad, but it’s not what I’d qualify as really nice.
As others have mentioned, the Inn at Abeja is all about the vineyard accommodations and is highly recommended.
The old Red Lion Hotel downtown is currently being renovated and will become a new outpost of The Lark. The first Lark is in Bozeman, Montana and looks pretty spiffy. It should be open next Spring. Michael Corliss (owner of Tranche/Corliss) has also purchased a historic building at the corner of 2nd and Main, which is the most prominent corner downtown. That building is currently undergoing renovation and will become a yet to be named boutique hotel, with a restaurant. Probably opening 2021. The old Oddfellows building across the street from the Charles Smith tasting room is also supposed to become a hotel, but construction on that one appears to be delayed for reasons unknown to me.
We live in Western Washington and frequent Walla Walla. (In our room at the Eritage now actually as I write this getting ready for appointments at The Walls, Abeja, and Garrison Creek today 
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I would highly suggest for a first trip to stay as close to downtown as possible. The Marcus Whitman is a great choice. I would definitely make sure to request staying in the original tower and not the new sections. Nothing wrong with them, very nice but not the same feel by any means as the original part.
A lot of our trips recently we have been doing VRBO and getting some great places downtown and has been a lot more fun than being in a hotel. Recently we had three couples and we stayed in a 7500 sq ft late 1800s “mansion” that was originally the home of the doctor that got the first hospital built in Walla Walla. It had been updated, but still had tons of old character. For three couples we stayed there for less than three rooms at the Marcus Whitman and were actually even closer to downtown.
So just another thought for lodging.