On the remote, press the Bluetooth button. The soundbar will attempt to connect with the most recently connected device. If the most recently connected device cannot be found within 30 seconds, the soundbar will then attempt to connect to the next most recently connected device. The soundbar remembers the last eight devices connected to it.
When attempting to reconnect to a device, be sure the device is on, its Bluetooth function is enabled, and it is within 30 feet (9 meters) of the soundbar.
You can also manage Bluetooth connections using the Bose Music app.