For largely unskilled uneducated labor Amtrak pays their onboard service crews good money and unparalleled benefits. IMO the chef and bartender are the most skilled as they have to be educated on serving beverages and cooking but what does it take to make up a bed? If you add in tips these people are doing very well. If they earn $150 per trip and do three trips a week they can add 50-70% to their compensation. I know professional people making less than that.
Sadly, the benefits at Amtrak are FAR from "unparalleled". The amount each employee is required to contribute to the company healthcare plan, provided by United Healthcare, is only slightly less than buying an individual, independent policy. Many companies have far better. Amtrak does not pay for sick days. For those employees who hold a regular route, missing a day because of illness generally means missing an entire trip, 60 hours or more, with no guaranteed way to compensate for the loss; this means that many employees report to work sick, putting themselves, their coworkers, and the general public at risk. Although Amtrak does offer vacation pay, it takes 7 years of service to get beyond 2 weeks' vacation.
I worked at a convenience store 30 years ago which was not unionized, but offered excellent wages, profit sharing, free healthcare coverage, sick pay, and personal days.
150 dollars would be about average per trip for tips, split between coach and sleepers. But it is impossible to work 3 trips per week, when those holding a regular job rarely work more than 3-4 trips per month.
Overall, an onboard crew member working an average of 40 hours per week is going to gross around 45,000 dollars per year...then you can subtract 3,000 for medical, 1,200 for union dues, 25% for taxes (depending on the state), etc. Realistically, the only way to earn a living wage at Amtrak is to get at least 200 per week in tips, given the locations of the crew bases (in expensive large cities).
As far as tipping, there is no need to compare diner tips to those in a regular restaurant. A dollar or two per person for breakfast or lunch is sufficient for adequate service, a bit more for dinner or if you are having wine. For sleepers, depending on the length of the trip, if someone is actually making use of the bed, 10 to 20 dollars per roomette and 20 to 50 dollars per bedroom - all depending on the level of service - is standard. In coach, tips are not expected or suggested, unless someone asks for non-disability-based assistance with bags, meals, etc. At these rates, with average occupancies, an attendant can scrape out around 200 dollars per average week in tips. Superior service (Vincent on the SWC, Hermenio on the CS for example) merits more, and these employees do average more....