HI,
Welcome to this site. I am getting married in Punta Cana April 17, 2015. We chose the Melia Caribe Tropical. Reason being is because it has an adult only section as well, which is what my fiancé and myself wanted. We first looked into Adults only and came to realize that some family members couldn't go if they couldn't take their kids with them. So we tried to make everyone happy by going to a family friendly resort and then my FI and I can get what we want by having an adult only section. So if that's kind of what you are looking for you can look at this hotel. The grounds look very beautiful as well. Check it out on trip advisor and perhaps add it to your list of resorts to research.
Happy Planning and let us know how it goes.