As a reply to my own question above. I stayed in Recoleta and went to chabad for shabbos day. Decent but not great. They do have a kiddush with some salads and a cholent. They have a restaurant called Luba which was actually pretty good. The kosher stores in the neighborhood of Once are quite small, sell cookies, bread, meat and cheese etc but didnt see prepared foods. I had brought Pom meals with me. I ate at Al Galope and a few other restaurants in Once. All fine. Went on a private tour of the city of BA that I got through a rentalocalfriend. I also went on private jewish tour. Both very good. Went elsewhere in Argentina which I will write about later.