My DW and I did a silver plan (wishes) add-on last Nov. and it was very easy to use the wishes for meals. Just tell your server when they come to the table. Often the server will offer advice on what to order to maximize the value of the "wish."
Some restaurant meals require 2 wishes.
We got a soup/salad, entree, dessert & beverage (non-alcoholic). This may have changed, so I would consult the guidebook for the program before ordering.