We tipped at Wolfgang Puck's Express too - the server was very nice!
I didn't see anyone tipping at BOG for lunch or breakfast. Matter of fact, once they brought out our food, I didn't really interact with any cast members. I had thought we may need to tip, but didn't see it happen. Of course, if someone did something extra special to help out, you can do so. It's not likely to happen for lunch, though.
Beware: the French Onion Soup and roast beef sandwich were both amazingly good (or I was just super hungry) - but I couldn't even finish half the sandwich after the soup! I'd go back again but share both! It's SO MUCH food!