Riau doesn't have night life as the western world, but people hang out in the street in the night. So just go out and see how the locals enjoy their evening.
The island of Batam is home to many clubs and bars, catering to the large Western expat population working at the engineering companies, and the younger locals. Be aware of prices, which are quite high in the hotel bars and clubs, and of illegal drugs, which are widely available but dangerous.
