Bluetooth isn't fully supported for now so this page is a quick draft for developers only. AsteroidOS uses BlueZ5 for its bluetooth stack. The LG G Watch uses a BCM20715 BT chip from Broadcom, this chip needs a proprietary firmware which is uploaded by the patchram systemd service. Once the firmware is uploaded an hci0 interface is created and can be used by hciconfig, hcitool or bluetoothctl. For example you can use the following commands on the watch via adb shell :

hciconfig hci0 up
hcitool scan