Agreed with others on the title issue- in these days and times “expert” does not have the ideal connotations. I like Robert’s suggestion of WineGuru. Wine Guide suggested above is also a good one.
I have to say, I like the concept. My background is primarily private equity and brokerage, but with a healthy dose of tech consulting for startups or post-IPO companies reorganizing things a bit. We are at one of those points- kind of like in 1999 when it seemed a million people had the best new concept in hardware or storage- when it seems like a million people have the next great app or online-based service/experience. So I tend to start off with a very skeptical mindset, but I think this could be viable as a starting point, though I think you will need some other broader related revenue streams to really make it something that could attract serious investment and generate strong long term revenues.
My suggestion would be to look at your current offering as the sort of Rolls Royce in a garage that offers many options centered around wine tastings. Less expensive options could be offering a wine selection along with some more beginner-oriented literature that lends itself to being examined and learned from in a party like setting. Maybe even make a game out of it- have trivia cards and the like.
And also- to the extent possible- get a little more serious with some offerings that can really teach a lot about wine on a budget. For example maybe sell a flight of 100% Sauvignon Blancs from different producers around the world- and another flight where they all come from the same vintage and area. The teaching materials can then emphasize examining how the different variables of local site, country, vintage etc. express themselves when you make other variables the same. Here your experts still come into play, but they write a single set of materials that does not require their personal attention for an actual online presentation.
You could also offer pre-recorded sessions that can be started and stopped etc- not the same as live, but less expensive and still something fun and new. Maybe here offer a comedy option. That would be awesome. Think of it kind of like comedy defensive driving school. And that would add a great deal of value and fun without the cost and hard-to-scale obstacle of a live online session.
On the wine side, I think this is all going to succeed or fail based on how you function as a buyer and retail seller of wine. You do not need the best of the best- but merely good introductory bottles at a decent price. The key is going to be that retailer who is buying wines that wholesalers want to move- and in great quantity. And where you will have to do battle is in taking in B to B+ wines that are tasty, but refusing to take C+ or less wines that are not going to be all that appealing.
When and if you get into a mode where you have a strong allocation of certain wines- then you can add additional revenue streams by offering mixed cases in future vintages of your wines that your tasting experience customers have purchased. Get them interested with a tasting of the 2014s of a given producer, and then in 2015 and beyond try to sell those same people the wines to replenish their cellars. If they want to do the live tasting again as well- great. If not, you still sold them a case of wine.
Just some thoughts off the top of my head. And my opinion is just that- I do not claim to have all the answers- but again I do strongly suggest you look at the business model as a whole from the perspective of using the online tasting interaction and other services as a vehicle to sell wine. If you just rely on the service and take whatever wines you can get, then you run into huge risks over time in terms of having a reliable supply of wines that are acceptable to you and your customers at generally steady and predictable price points. Plus you risk not having the supply to get repeat business for your current offerings. A small percentage of your customers may someday be active members on boards like this- the majority who are happy with what they are tasting are going to be happy if you can sell them more of what they just tried and liked at a competitive price.
Best of luck!