I've been to Punta Cana a few times and i recommend going to:
1. Mangu - inside Grand Flamenco
2. News - inside Bavaro Princess
3. Pacha - inside the RIU Hotels
There are other bars such as Hurricane Cafe, Chotis, Highwaves, Soles etc.. that are good to check out.
I'm goin in June again to Bavaro Princess ...
Hope this helps.
Happy Travels
