I am with Alf and Tab on dissing bluetooth. However, it may fit your bill just fine. Security probably won't be an issue if you are just listening to something...someone else may jumpin but I think that's probably the extent of it so long as the bluetooth cannot be used to control your TV or stereo.
Bluetooth has security issues and multiple quality issues. I have a couple of Mosconi amps in my truck and I have a wifi link I can use with them, bluetooth or a hardwire. Bluetooth has sound degradation issues....but most people can't really tell or have the equipment level to realize the issues.
If you can find a television and speaker device that can transmit and receive using wifi or other frequencies that would be so much better. We had wireless headphones for the boys 15-20 years ago hooked up to the VCR and TV in the van which were great. There was a transmitter hooked up to the TV RCA plugs that sent a very good signal to the headphones. Heck, it was a ratshack product and it sounded great.