Pocket version 5.0.2 brings AirPlay support even when Pocket is closed or device is asleep:
This is why we’ve integrated full AirPlay support in our latest iOS release. With the help of Apple TV, you’ll now be able to watch all the videos you’ve saved to Pocket on your very own television. Your videos will even keep playing when you exit the Pocket app, perfect for multi-taskers who want to check their email, Twitter, or simply just lean back and relax. link
My “pocketing” doesn't typically include a lot of video, but background AirPlay sounds very spiffy in a watchlater kind of way.