There's quite a few items you can check and if you have some further information this will help :)
- Are these SSID"s using the same VLAN? Is the routing to/from these VLAN's correct?
- Is anything being denied by the firewall/3-way hand shake completing? "show datapathsession | include xx.xx.xx.xx" will show you this. Look for a D or Y flag if there is usses?
- Is there any difference in the assigned roles? "show rights xxx" where xxxx is the role assigned to the iPad.
- Is there any upstream firewalls or such blocking the Gmail traffic?
- What ArubaOS are you using As AirPlay was only included in the later releases.
If you want to attach a copy of your configuration we can review the settings
Rgds,