Emlos,
The inshore fishing in the Punt Cana area is not bad. Your best bet is to just walk along the beach till you find a secluded area and let fly. Wade out and run some streamers along the inside of the barrier reefs. Jacks, Cuda, Ceros, and the occaisional Snook can all be had.
Better yet rent a local and his yola and head to a river mouth and go for Snook and tarpon.
Just be prepared to draw a crowd when you start false casting. Fly fishing is very alien to the locals.
Tony C.