DIAGNOSIS The soundbar is not in Bluetooth pairing mode. It defaults to seeking an audio input from the TV. The LED needs to be in a specific state to be discoverable.
FIX Press and release the 'Bluetooth' button on the remote. The status LED on the soundbar should begin blinking blue. On your phone, go to Bluetooth settings and select 'Bose TV Speaker' from the list. If it connects, the LED will turn solid white.
IF THAT DIDN'T WORK Perform a Bluetooth reset on the soundbar. Unplug it from power for a full minute. While it's unplugged, turn your phone's Bluetooth off and on. Replug the soundbar, wait for the startup chime, then immediately press the Bluetooth button on the remote.
HEADS UP The soundbar can only remember one paired device at a time. If you've paired a different device previously, you may need to forget the 'Bose TV Speaker' from that old device's Bluetooth menu before your new phone can pair successfully.