Having worked in the US before, the figures above look fine.
However on a recent trip, I noticed that everyone seems to be looking for money for doing anything.
The rationale for tipping waiting staff at least 15% is due to the fact that their basic wage is so low. Bar staff get paid much more, but actually do very well in tips as well.
Personally, I don't tend to tip housekeeping staff, staff in Starbucks/Dunkin' Donuts etc.
I may tip the concierge if they do something for me, e.g. in Chicago our shuttle was running late and the guy got me a car at a good price.
Aside from waiting and bar staff, it is entirely at your discretion.
It is in theory discretionary to tip wait staff, but unless service is poor, expect to hear about it, e.g. the American staff I used to work with had no qualms about running out the door and confronting the customer if they received no tip/small tip. If you don't tip bar staff, don't expect good/fast service.