Would "I drink beer only at the bar" be "אני שותה בירה רק בבר"? With the same logic as in English?
Well, I know it's mostly british english, but pub should be accepted, especially since many of us are using pubs פאבים
The suggested answer makes it sound like beer at the bar is different. Surely it should read "I only drink beer at the bar" or "I drink beer only at the bar". ("In the bar" has yet again a different meaning... I wonder what was originally intended!)
The bar can refer to the whole establishment, the same way a cafe does, not only to the bar where the bartender stands.
I agree with the other comments that "at the bar" is correct here. The only time I would say "in the bar" is if you are distinguishing from outside the bar. For example, "I was waiting for my friend outside his favorite bar, but he was still in the bar."