pandahill

Thanks to wokwon and Chucker's comments I have a solution.
 
For the benefit of others here is what I now do:
 
Let Skoda bluetooth connect to phone as usual when starting the car From the dash maxidot display select "Phone" and go to "Bluetooth", "Media Player" Then there should be an option like paired devices and Disconnect. This disconnects the bluetooth media player, but not the phone pairing.  
 
Phone calls and Phone Sat Nav instructions will now come through the stereo when Radio or other in car media is playing.
 
Note, this works on my MY12 Superb Ambition with Bolero Stereo and iPhone 5.  It may not work this way with other models...