I think $1 per drink is too much in most situations in the US these days.

In the days - not that long ago, maybe 5-10 yrs - when bartenders were career professionals who knew the job and knew their drinks, could suggest interesting things etc, I used to tip that much, sometimes more, living in NYC. But those were pros and they deserved it for what they did.

These days, when you cant even ask for a relatively basic cocktail without getting asked by a wannabe-actress to explain it, I dont really top any more in the US for just drinking at the bar - the folks there are probably les skilled than a so-called coffee "barista" at Starbucks. Maybe a couple of bucks at the end of table service for brinks but that is about it. And living in Europe now, I dont really tip at all at the bar, not really the culture for the most part.