score:9
Let me answer my own question. I just got back from the trip and I found out that motorbike rental shops are abundant in Philippines (but usually not advertised online) . The price is usually about 600PHP (12 USD) for one day. Even in rural places where there are no renting businesses it is easy to arrange for a rental with locals.
I rented 6 different motorbikes throughout the country and had no problem whatsoever.
Upvote:2
You can find a bike rental in most any city you're in. Just remember to bring a separate ID when renting. They will require you leave one with them and you don't want to leave your drivers license.