Q: Apple TV 4 how to stream music or movies in to my home theater?

This information may help you Set up your Apple TV (4th generation) - Apple Support

Simply purchase one of these:

http://www.amazon.com/J-Tech-Digital-Premium-Extractor-Converter/dp/B00BIQER0E/r ef=sr_1_1?ie=UTF8&qid=1463492983&sr=8-1&…

Route the ATV4 output into the J-Tech HDMI input, J-Tech HDMI out to the TV or projector, and the J-Tech optical output to your Bose.

If your theatre has a TV check it for a built in extractor and use it.  Look for optical out...

I personally have a projector setup in my theatre so this was not an option.  I used a different model J-tech with a multi HDMI input switch to allow switching of HDMI inputs to my 1 HDMI input projector.  It has worked flawlessly and allowed me to enjoy Dolby 5.1 though my Yamaha setup without HDMI inputs and just opticals.

Use the HDMI which is audio & video.