Another option would be to do dessert from the Main Street Bakery and cop a seat in the Noodle Station area. You would be so much closer to WISHES with the added benefit of seeing Tinker Bell fly right over your heads

Or monorail over to the Poly and take your drink out on the beach to watch from the lagoon. IMO It seems a bit much to expect full seating and service from the California Grill for a single shared dessert; be sure and disclose when making the ADR and they can tell you what charges will be and if they accomodate your shared single course request.