Listening with bluetooth headphone with new Chromecast with Google TV is a mess. When you pair your device with the headphone for the first tiime It works well. However if you turn off your headphone and turn it on again Chromecast connect to the device but doesn't send sound anymore even if you disconnect and reconnect no way it the sound doesn't work anymore. You have to forget the bluetooth headphone and pair it again and again again. I don't know if you are facing the same problem
Somewhat unrelated I was having a Bluetooth issues with using an xbox controller, seems like the signal is really weak and only worked well within three feet from the dongle, about 6 feet and playing became super laggy. Also geforce now kept constantly freezing. I had to return mine.