Just came back last Tuesday, and most places in town seemed dead as compared to even a few months ago.
For a beer with a younger, college aged crowd; try Okie Dokie and the Parque de los Estudiantes across the street. You can also try the Parque Duarte and the nearby businesses.
For a more upscale crowd, you can try Fly Lounge (excellent food, a bit expensive by DR standards) or Lite Lounge. Also close to those 2 places, there are 2 liquor stores, where you can hang out and have a drink with a mixed crowd.
For the nightclub scene, try Cacique, the place across the street (recently changed name from Cafe Claro), Kareta, or Makarao.
La Vega is a relatively small city, where a lot of people know each other, and the places that I mentioned are well known to most residents. Enjoy!