Hi Denise,
You can make a reservation for them somewhere else in the park to eat. You can book it online or by calling 407-WDW-DINE. Your teens can pay for their meals with the Disney Dining plan if you are using this option or by cash. If you have authorized them to charge to your room, they could use this option as well.
If your teens know about your trip, have them go online to look at the restaurants in Epcot. They may like
Teppan Edo where they can watch their dinner being cooked in front of them. They may enjoy
Biergarten in Germany or
La Hacienda de San Angel in Mexico.
As for the two choices you picked, the
Coral Reef is a cool dining experience but if seafood is the reason for choosing this restaurant then
Cape May Cafe or the
Flying Fish are great choices. The
Garden Grill is a character dinner in a revoling restaurant. This restaurant serves food grown in the Land pavillion where it is located. The food is served family styled and it is good.
They could also go to the
ESPN Club which is on the Boardwalk for dinner as well.
Wishing you a magical vacation!
Beth