Why are my favorite stations not showing up in the B-Fi Control App's 'Favorites' section?

When you first open the app, on the main menu there is a "Favorites" link.  However, this is not tied to any specific service, and is used for saving favorites songs you have stored locally (either on your source device or elsewhere on the same network).

If looking for previously saved stations, like those found within TuneIn or iHeartRadio, then you would want to check the 'favorites' while you are within the corresponding application.