If after having paired the speaker to the network, you can't find the Phorus product in the list of available devices, you may need to update it. CAP version 1.0.1.017 or later is capable of AirPlay streaming.
To verify your version, go to Settings and then About. You should see your Phorus product there, and you can verify the CAP version. If it says 1.0.0.099 or lower, you must update it using a Phorus app from the appropriate app store.
If you are still having issues updating or playing, please contact support.