See
http://dr1.com/directories/hotels/me...tropical.shtml for more details on the hotel.
If you visit Punta Cana you will be in the far east part of the island. While you can see St. Thomas/St. John easily in a day, note that the Dominican Republic is a big country -- 18,000 sq miles vs. 31 sq miles for St. Thomas and 20 sq. miles for St. John. The largest hill in St. Thomas is 1,556 ft. compared to 10,000 feet for the Dominican Republic's highest mountain.
In other words, unless you do a lot of driving, you will only see a small part of the island. The trip from Punta Cana to Santo Domingo is four hours by car.
Check out
http://dr1.com/travel/puntacana/ for information on your area. If you have time, venture out to see cosmopolitan Santo Domingo (the capital), or La Romana with its town, Altos de Chavon and Marina de Casa de Campo, also the beaches at Bayahibe and Dominicus (enter via the public beach between Dominicus and Iberostar hotels).