If you ask the staff, they can help point you to the meat that is marinated with sauce using gluten. They are also willing to send along soy sauce with no gluten (presumably Tamari sauce but I didn't ask specifically). Note that the grill will be cooking other meals with the marinade though, so if you have a really strong allergy there's not a good way to avoid it other than ordering their salads. Otherwise, the food is great and it's a fun experience!
— Somewhat
— No gluten-free information on the menu
— Some
— Excellent