Public transportation on Bintan is very limited, and is probably not worth the effort unless you have a passable command of Indonesian and a lot of time on your hands. Virtually all visitors use taxis or rent cars.
By taxi
Taxis compete furiously for your custom and cutthroat bargaining is a necessity. The safety of these is dubious though, and it is generally advisable to avoid the taxi touts at Tanjung Pinang's ferry terminal entirely and arrange transportation with your lodgings.
By Minivan
Bintan's embryonic public transport system consists of white minivans known as mikrolet or angkutan kota angkut. One set of vans runs around Tanjung Pinang, while another set covers the rest of the island. The only way to tell where they're going is to yell out your destination as they pass, and to get off, just yell kiri. You can transfer between the two near Bintan Centre, also known as Batu Sepuluh Marker 10. Fares within the city are a fixed Rp. 5000, fares outside it are negotiable; going to Trikora might cost around Rp. 40000.
By car
Car rental could cost between S$50 - 100/day for a sedan, depending on how far you go: all the way around the island, visiting Tanjung Pinang, the east coast, and the resort belt in the north would be a 4 hour, 200 km venture, while a short day visit to Trikora coast might be had for $50.
By Scooter
Prices about S$35/day or 20/half a day, fun and convenient way to hop from beach to beach or even travel quite a long distances over the island. They will provide you with a helmet and price of the gasoline is cca Rp10000/2l bottle every shop near the road sells that