Hello Robert,
It is OK to use the management interface as your internal wireless network interface as long as you are OK with that design (clients and management in the same subnet).
Basically, if you want to put WLAN traffic in a different WIRED vlan, you create a dynamic interface for the desired VLAN (controller > interfaces) and then select the desired interface under the WLAN configuration.
On the switch side, you will need to make sure that these new vlans are being trunked to the WLC.
The following diagram explains the interface usage on the WLC platform:
http://www.cisco.com/en/US/docs/wireless/controller/7.0MR1/configuration/guide/cg_ports_interfaces.html#wp1278618
-Pat