Currently, the public ferry from Batangas has been "upgraded" and will only be docking at the Muelle Pier in Puerto Galera proper, which means a 10 minute jeepney or trike or van ride into Sabang. Only the slightly smaller wooden bancas from Berberabe will be docking at the Sabang beach pier.
However, you stated that you've arranged private transport through El Galleon, which is most likely on a boat owned by EG, departing from Berberabe, arriving directly at El Galleon's private dock. You might want to email El Galleon just to confirm, but that's always been my experience in the past. They run a great operation, I wish you luck on your trip, and hope you have a great time!
BTW, do you mind if I ask when your trip is?