In US and lots of countries bar tenders normally are tipped.

However in US we now seem to have an expectation of a tip.

Parents and i were out to eat.. Waitress was awful. Bill was like 50 or so. Put 60$ and waitress assumed without asking she just got to keep it all. We had to ask for the change. Then put $5 on table. No matter how awful we leave 10% since waiters are paid less than min. wage.(Employer is supposed to make up difference if they don't earn enough in tips, but lots don't, so always 10%) Waitress grabbed money and scolded us that 20% is expected, thus she expected $10. She delivered food to each at different times, we had to ask another waiter to refill drinks, etc. Now she expected 20%!