Yes such a question can be asked not only to bartenders, but to many segments of the population, how they are able to survive on the minimum wage they are paid. I can navigate to this web-site , so you can read about the minimum wage and what various thinkers and experts think about it. There are very good essays with factual data, I have learned a lot and look at this issue more broadly and holistically. I recommend reading it, then many questions will disappear.