I don't see what health bennies have to do with this.
I've been a waitress. Waitstaff are paid x amount of dollars plus tips. If x plus tips do not equal minimum wage, the company has to supplement the waitstaff wage to bring it up to minimum.
That doesn't usually happen. If a server is good (even if a server is sub-par or mediocre), they will make better than minimum without any help from their employer.
Managers and supervisors are paid salary or an hourly wage which would be NO LESS than minimum. Their wage scale does not include tips. They are not entitled to tips.
As for health bennies, I'll bet you are wrong when you state that the company PAYS for them for part-timers. The company probably offers health plans that the part-timers can pay into, which a lot of companies do, but that's different. Your statement suggests that part-timers are getting bennies entirely at the company's expense.
Firstly, health benefits do cost the company --- otherwise why would companies not offer them to part-timers? This does not mean that the company pays for the ENTIRE cost of those benefits, of course.
Secondly, I personally do not think that waitresses should give even a penny of their tips to supervisors. Tips are cutomers' acknowledgement of the PERSONAL effort of the waiter/waitress.
Starbucks has a socialist/collectivist mindset. As part of this "equality," the company offers benefits to part-timers, which companies very rarely do. The other aspect of the SAME mindset is, since we are all in it together, let's divide the tips. My point was that barristas like collectivism when it is in their favor and rave against it when it is not. That inconsistency is what I pointed out.