I don’t have specific shop recommendation, but would HIGHLY recommend seeking out Uruguayan Grappa. Extremely unique and the examples I have had have been shockingly good…
You’ll definitely have options in both cities. In Buenos Aires, it seems like there are tons of options. A couple of my favorites when I was there in August were:
La Malbecqueria
Uco
Aldo’s Wine Bar
I went to Don Julio for dinner and they had a deep Argentine wine list.
For Montevideo, you have to go to the Montevideo Wine Experience. Liber is the main guy there. He speaks perfect English and has a lot of goodies to open and even opened a 1996 Uruguay Cab for me that was still very alive and wonderful. There is a cool Italian place in Montevideo called Panini’s that has a bunch of great Uruguayan wines and it had one of the best South American wines that I’ve ever had (2011 Osiris Tannat).
Make sure you try to deep dive into the Tannat in Montevideo. I was beyond impressed with what the grape can be and I hope you will as well
Buenos Aires:
La Brigada – parrilla
Taberna Baska – Basque food
Montevideo:
Go to the Ciudad Vieja (old city) and make sure to visit the Mercado del Puerto. You can have a glass of medio y medio at Roldos (a classic!) and then lunch at El Palenque…
Don’t have winery or wine bar advice, but had a couple great dinners earlier this year. Manzanar in Montevideo (Sofitel across the street is the best hotel in town) and Gardiner in Buenos Aires where we sat in the wine room (pic attached). Great vibes in both. Didn’t have control of the menu so can’t comment on wine lists but guessing Gardiner would be decent.
btw, you should look into taking the ferry from Montevideo to BsAs. It’s a lot more relaxing, basically costs the same as a flight, and it puts you right in the center of BsAs
For wine shops, check out Lo de Joaquin Alberdi in Palermo. Great store and they always have interesting wines open. Look for the JA! sign from the street!
Lo de Joaquin Alberdi
Jorge Luis Borges 1772
It’s been five years since I’ve been in BsAs, so any restaurant/wine bar recommendations are likely stale. The aforementioned Aldo’s was very good. Watch yourself in San Telmo, however - best to take a taxi to the restaurant.
And Keith is spot on with the ferry to Montevideo/BsAs reco.