I've been going to Spanglish the past few weeks and I really enjoy it. I think it's possible to make friends there as well. Friday, after Spanglish, a bunch of us went out afterwards for some pizza and I met and hung out with some cool locals.
I usually go on Tuesdays and Fridays. Tuesdays at Sugar is a Pub Quiz, so it's a little different. You spend about an hour-and-a-half with the same three or four people answering questions. I enjoy it, but if pub quizzes aren't your thing, you may have a different opinion. Fridays is at Sabbia in Recoleta and might work out well for you since you live in Barrio Norte. It's the traditional speed-datingish type of Spanglish, but it's usually packed and a lot of people hang out for awhile afterwards so you can spend more time with folks.
Hope this helps.