Although many folks choose to ignore it, please remember that the California Grill has suggested attire guidelines that are not as casual as restaurants inside the theme parks. You might want to take this into consideration when figuring out your timing. Personally, I'd probably want to change or at least freshen up before heading over to the restaurant itself. While you would be able to get from Disney's Animal Kingdom theme park to the Contemporary Resort in time for your reservation, you would not have time to change into appropriate attire for the restaurant before dining. Unless of course your typical park attire is business casual. I'd suggest trying for a little later seating.