It depends on the TV model and Bluetooth device. Bluetooth headphones can only be used with the following models. Please make sure that your model is the list.
Applicable TV models
A2DP (Bluetooth headphone) functionality is applicable for the following TV series (after OS nougat update):
NOTE: On the setting menu, you can check whether your TV model supports Bluetooth headphones or not. If your TV supports Bluetooth headphones, A/V Sync will show under HOME> Settings> Sound in the TV category.
Applicable Bluetooth devices
These Bluetooth headphones are supported.
For other Bluetooth devices, if the device supports A2DP, it is highly likely that it can be used. However, Sony does not guarantee the operation as a manufacturer.
In the event of issues, such as no sound coming out even when using applicable products, refer to the following FAQ:
Troubleshooting for the Bluetooth connection with the audio device on Android TV released in 2017.