How is a bar owner rent seeking? They are providing a good and charging market prices for it. If bars in the city got together and introduced a bar-density limit within the city so as to limit the number of bars that can exist and thus allow them to raise prices, that would be rent seeking. If a bar hired a bunch of people to attend town hall meetings preventing new bars from opening up and allowing itself to raise prices - that would be rent-seeking.

If prices of drinks are going up naturally because people are making more money, "rent" for real estate is going up, etc. that is not "rent-seeking".

Not sure if I'm missing a sarcasm tag in your comment but most places in the US restrict the number of places selling hard alcohol by having a restricted number of liquor licenses that trade on the open market like taxi medallions. In San Francisco for a restaurant this will set you back a cool 1/4 million[1] and the type 48 license you need to open a bar seem be sold so rarely in San Francisco I can't find any price reference online.

[1]http://www.mercerrestaurantgroup.com/how-to-open-a-restauran...