Route 66 - mostly anything works.
Il Mascheratti, La Casa de Mi Abuela, and Mexican - long pants. Closed shoes recommended but not enforced.
El bodegon - long pants and closed shoes.
Buffet - no wet swimwear, dry swimwear OK(lunch). Anything "dry" no swimwear on nights. You will want to do Buffet on Friday for great typical dominican food (chivo, roasted pork, dulce de coco, dulce de leche, habichuela con dulce, arroz con leche, etc.) On Saturdays also recommend buffet go eat great great GREAT imported churrasco accompannied by grilled zuccini. Make sure it's medium well and well seasoned... so mouth watering!