Stream Music from iPhone data network while connected to non-internet Wifi??

I setup a non-internet AirPort wifi network in the ranch. No internet available there. So I used to be able to stream music to my iphone via the data network then use AirPlay to send the music to the AirPort Express that was connected to my speakers. I would be connected to my WiFi network in order to send the music to my AirPort Express but the data was being downloaded via the Data Network. Since the update to iOS7, I'm no longer able to download music via the cellular data network if I'm connected to a non-internet wifi network.

Here is what I've tried:

a. Teathering from my iPhone but can't feed the wifi network you are joining via teathering.

b. Settings/Cellular Data On.

c. Data Roaming on and off

d. Use cellular data for: All are checked to yes.

It used to work with iOS 6, but no longer an option with iOS7. Any suggestions??