You can't even really use the word "salary" when it comes to bartending. It all depends on those people on the other side of the bar as to what you're gonna' make. It usually doesn't matter much what the company pays unless, maybe, you're at a union casino that pays 16 dollars an hour or something. Paychecks are merely icing on the cake and nothing more. It all depends where your working. There's a common misconception with people who don't know the idustry at all that all bartenders are going to make roughly the same. These same people usually have no idea how much money can be made in the field. At a dead, hole in the wall bar you could be making 300 dollars a week. Or, you could be a restaurant service bartender making 30 dollars a shift. On the other hand, if you're in a high volume bar in one of the countries major markets(Vegas, L.A., N.Y., etc) you could be making 2,000 a week, or better. All depends where you're at. You could work at a busy bar with gambling, the right person hits a royal flush, and you just made 100 dollars for serving a beer.
Making more money is just common sense. Either work in a busier place, or improve your following, and improve it with tippers. Two people who also work in the industry can be worth ten people who don't to your tip jar. Building your clientele should come naturally.