There are quite a few choices nearby that cater both to the tourist as well as providing a chance to go 'local'.
On Playa Rogelio there are beach shacks that do wonderful Dominican style meals with fresh fish, fried potatoes, plantains and many other items. Nearby on Playa Magante you can eat at Playa de los Pirates where they have more tourist oriented food, Red Snapper, Dorado, Blue Marlin, steak, shrimp etc combined with tasty sauces.
In Rio San Juan a couple of favorites are Estrella's (which also has great baguettes and croissants), Open all day and great stop for breakfast. And the Pizza place right next to the lagoon. It doesn't show up on Google maps but has great pizza and Italian dishes.