Bonao's got pretty mountains and a couple of nice places to take a trip to (rivers). There's a hotel there called Aquarius (never stayed there so not sure how good it is). You'd be pretty close to La Vega or even Santiago.
Monte Cristi is actually pretty decent, but a long ride from Santiago. When I visited I drove from Cotui and it was kind of late so I stayed in Mao at that new hotel
http://www.dr1.com/forums/central/99992-mao-bananas-big-luxury-hotel.html and drove the next morning to MC. If you like goat there are about a gazillion goat "restaurants" on the way there. Coming into MC we got hungry and asked around and they told us about this restaurant called "Dona something" I think It's Dona Luisa...not sure. Anyhow it is when you're coming into town you have to turn right of the main road and go through a residential area. The place had good food and it's in a quiet place...I would go there again.
Then just continue driving straight eventually you'll make it to El Morro which is stunning, but the sea is very rough. We swam a little, but it wasn't really that enjoyable. There are a couple of hotels in MC as you go towards El Morro. They looked pretty basic (We didn't stay the night). There's a small "Malecon" where families gather to grill, drink, etc...it looks like a lot of people take boats to an island or go deep sea fishing which we didn't do, but it looks like it could be fun.