Just because it is illegal doesn't stop some places. Last year the waitperson in Pineapple Pete told me the 15% added was broken down as 10% gratuity and 5% TOT and that I should leave 5% more for the gratuity to make it a 15% gratuity. I just paid what was on the bill and told him to have a nice day.
Jimbos is just open with the fact that the TOT is added as a separate line item.