Can I connect to any AirPlay device from the WatchOS 3 Control Center? In WatchOS 3, there is an AirPlay button at the very bottom of the control center.



When I press it, the only option I see is Apple Watch.



But on my iPhone, I'm playing audio from SoundCloud. I'm there able to assign the audio playback to AirPlay devices:



As noted in the image, I'm not using a real AirPlay device but a virtual one, via Airfoil playing on my Mac. But it should still behave like a real AirPlay device.

So, is this new button in the WatchOS 3 control center just for "AirPods" and the like?
On the Apple Watch, go to the Settings app, go to Bluetooth, and pair each of the devices you want to use.

The Apple Watch is connecting directly to the device by Bluetooth, not using your iPhone's connection.