Go thru Airport, it will set an internal IP address of sorts. You will have to recreate address if you shut down as Airport will not save. Use this address in settings when you open JRemote. You do not need internet or cellular access nor router provided both are Apple devices. I do this from Mini and Book all the time.
Now with Panel, you have the best of both worlds, Open the App on your pad, enter access number, hit streaming on media computer, and away you go. No server, Router, but you will have to enable a hotspot from your cellular device. Using data is justifiable as you are getting Flac ( red book ) quality streams. Excellent