I think all experiences on this will be highly variable for virtually every aspect ofyour experience. If they're receiving tips, they are supposed to report it; not doing it isn't a fringe benefit, it's just the government electing not to pursue the matter.
Likewise, some bartenders will pull hundreds based on location, their appearance, their social skills. Others will either get no tips or very few for a whole night. Some bar tenders wil work high volume bars at clubs and process hundreds of sales a night with minor tips. Others will work a bar in a restaurant or a hotel and get maybe a few customers a night.
There really isn't a blanket understanding of bar tender wages simply because it's incredibly dependent on factors outside of the work itself. Whether or not it's a long term career is kind of irrelevant; I don't think too many people go into bar-tending with the idea that this is it for their life, it tends to be a failback when other options just don't pan out. Regardless of how long they do it, while they're doing it, if a city wants to have these workers and bars as part of a city life, they should probably make an effort to ensure that the workers have a place to live and can eat at least, else they will have to leave by necessity.
Like, the idea of a career job versus a non-career job seems very arbitrary here; the expectation of a living wage is kind of basic for work - it's why most people do the work thing. Sometimes it's labor of passion, but a lot of times, it's "I can do this and someone is willing to pay me for it."