We use AirPlay to listen to radio (well TuneIN on an iPod Touch) on the stereo via Apple TV.
Wonderful it is but 100% reliable it is not.
It is about 50-50 whether or not the share icon is available when we pick up the iPod and run the TuneIN app.
If it is not there... wait... wait some more. still not. Switch to settings, disable WiFi. Count to five. Enable WiFi. Back to TuneIN, Again about 50-50 chance share icon will appear in the next 10 seconds.
If not, turn the TV on and switch to the Apple TV. Use the Apple Remote to verify that is working. Again about 50-50 chance that "wakes" something up and the share icon will appear on the iPod.
If not, hard reset the iPod (hold the buttons down...) Wait for reboot. Re load TuneIN. Almost always that gets the icon... and we can listen to our radio stream!
Once connected it is great. Until it is connected not so great.
AirPlay issues appear to be WiFi related. Shortly after getting the Apple TV we realized that it would work best with its own (non conflicting) dedicated WiFi. That helped a lot.. but still not 100%.
In theory we could subscribe to the same stream via the built-in radio application on Apple TV. But turning the TV on and navigating through the menus to select it and then turning (just the) TV off is (usually) even more work.
We only put up with it because the radio station we want is remote and cannot be picked up via the antenna in the stereo. In times past the local cable provider used to add the FM signals to their feed, but those disappeared a few years back so they could free up spectrum.