If you use the buffet price sticky over on the restaurant board, they include tax, but if you look at the menu boards outside the actual restaurant, they do not. I can't think of any QS or TS that include the tax on the menu.
The only ones I know of that include tax are Cinderella's Royal Table and the dinner shows (Hoop De Doo, Spirit of Aloha and Mickey's BBQ.) Its possible there are more but these are the only ones I'm aware of.