My friends and I have included El Bonanno as part of our Sunday La Latina route for a while. If you're looking for a bar with space to duck into when lots of bars are packed, this is a good choice. The owner takes a lot of pride in his place, his drinks, and his tapas, and that's always a good thing.
Among things to like about El Bonanno: they have their own house vermut, and while it's a little too sweet for me, it's still nice to find that unique taste. The tapas are different and you can tell that thought is put into them.
Downsides are that, through the years, the service has fluctuated between friendly and... not so friendly. Once I was poured a suuuuuuper small pour of wine and asked if that was the normal pour. Grumbling, the bartender told me it was, but he'd pour me some more because I'd complained. The last time I visited, I had another small pour, but decided to just let it go. The service at the moment is friendlier than past visits, so that's a good change!
TL;DR- not my first pick in this bar-packed area, but also not a waste of your money if the mood strikes you to try it out! read more