I work in a hotel bar, so it's quite expected. However, if you only work in a regular bar, I don't see why you would talk to him. Sometimes the best way to support your waiter is in silence with a good tip, a kind gesture of assent and a “thank you”. Hospitality workers often deal with a mix of personalities throughout the day.
A friendly, respectful guest who doesn't demand attention is often your favorite type. Bars are social places, and it's frustrating for the waiter if you're talking out loud to someone who isn't there talking on a cell phone.
