Possible to use Apple Watch to adjust volume of TvOS or Safari on MacOS? I want to use the wheel on the Apple Watch to adjust the volume of whatever I'm listening to... it could be 


Air Pods paired to MacOS (iTunes works, but Safari or other apps don't)
Apple TV speakers
MacOS speakers on a MacBookPro


How can I use Apple Watch to change the speaker volume in the above situations?
This or this might help.

You can change the AirPod volume from the now playing app.

If you're controlling your now playing on your MBP through the watch, the same might apply - otherwise I don't think it's possible at the moment.