It is valid for all members of the party booking the AAA vacation package. You do need your voucher for entry; they check it carefully, and you need to tell them the # of people on the package when you make the reservation (which of course needs to match the vacation package).
It really is geared for kids. We saw it in July and had the Fairy Godmother. She read a story (literally read a story) from a book to the kids. Kids sit in front, and the adults sit in the seats in the small theatre. After the story, kids can get photos taken and autograph books signed.
It's cute and relaxing.