You can't make a PS at the Rainforest Cafe at DTD, but you can call the restaurant directly and make a regular reservation. I don't know the phone number off hand, but you can get it from
www.rainforestcafe.com. That's what DH and I did for our upcoming trip. You can also view their menu on the website as well.
We've been to three different Rainforest Cafe locations on several occasions (San Francisco, Vegas, DTD Anaheim) and it's always been about the same experience every time. The food is always pretty good, and the service is generally pretty bad (service at DTD Anaheim *was* better than the other locations, maybe it was Disney magic). This is always preceded by a very long wait (sometimes a very, very long wait). If you have to wait a long time it's really not worth it unless you're there for the experience and not for the food. It is fun and a unique/unusual experience/atmosphere. But if you're there just for the food, skip it. We're going just because my DH loves it. I could basically take it or leave it.
They have very good burgers and fries (huge), and some sort of wrap sandwich I remember that was really good. Also the salads are huge and very good, as are the pizzas. Our favorite thing has become the fried chicken, which isn't really fried chicken in the usual sense. It's more like deluxe chicken tenders with mashed potatoes and vegetables. It's usually very good, and I'd recommend it. I've never tried the desserts, however, because after the huge meals, I've never had room!