I just referenced this collection of information and was reminded of its value. If you want to know about lots of things that you can do, already did or are considering doing in the area, check it out. There is at least one inaccuracy (I believe Barco Bar, one of my favourite places, has closed) but you can absolutely still use it as a reference.
A bus ride or relatively cheap cab ride can take you all around Bayahibe and Dominicus and into La Romana too. Stop at Jumbo in La Romana to pick up your stash of rum for selection and the cheap price. While there, take a look at the jams made from local tropical fruit and pick up some music. Grocery stores tell you a lot about a foreign culture!