Bluetooth tethering is one of the many ways to share the wireless connection of an Android device with another device. In my case, the Android device was a Moto G which was connected to the home wireless network. The other device was a MacBook Air on which I needed internet access.
The steps I followed to get internet access on the MacBook Air from the Moto G were simple:
Connect to the wireless network on your Android device. Ensure that you can access the internet using this connection.
Turn on Bluetooth on the Android device.
Enable the Android device to be discoverable on Bluetooth. By default, this is not enabled.
Open Settings > Wireless and networks > More > Tethering and portable hotspot. Enable the Bluetooth tethering option.
On the other device, turn on Bluetooth and pair with the Android device.
On the other device choose the class of the Bluetooth pairing as LAN or Network Access Point. For example, on the MacBook Air I chose the Bluetooth logo > XT1032 > Connect to Network.
Bluetooth tethering is useful for devices like MacBook Air, which do not support other tethering methods like USB tethering.
Tried with: Android 4.4.2, Moto G, OS X 10.9.2 and MacBook Air 11-inch Mid 2013