Assuming the iPhone app works on the iPod Touch, perhaps you could try this ...
1 - Turn on the mobile hotspot / tethering on the Android phone
2 - Have your Ipod Touch / old Iphone connect to that wireless hotspot
3 - Run the apps that require network connectivity on the iPod Touch like normal
I have a similar setup in my current Mazda with the Pioneer AVH-P5200BT head unit and it seems to work well w/ Pandora and Spotify.
Just an idea
