Yep! It's one per person. As mentioned by a previous poster, some of the deluxe or appetizers for two can be shared by two people on the DDP. For example, Raglan Road has several apps for two.
If you go to Jiko, their appetizers and dishes from the cooking place are quite expensive, but since you're using 2 TS credits, each person gets an appetizer. I think other signature restaurants have the same policy. Jiko will also make a chef's choice appetizer sampler for two, as well, on the DDP.