Express is a CS, Cafe is a TS. You can use dining plan credits at either.
There is also the Wolfgang Puck Upstairs Dining Room, a more upscale choice that does not accept the dining plan at all. You should also remember that there are two Wolfgang Puck Express locations at DTD. The Marketplace location has more seating and a more extensive menu than the West Side location (which is right next to the TS restaurants)