help with wireless, vlan, subnetting, iptraffic, cisco controller and route

I have a building wirelessly connected to another building. Routing of vlan’s and dhcp are done on a cisco router in the first location. I have since set up wireless access points in both locations and cisco wireless controllers in both locations. I am running out of IP addresses at both buildings. My wireless technician says that I can only pull IP addresses from the wireless controller on the same subnet. I need a resolution to this as I am running out of IP addresses when a wireless device attaches to the network. Any ideas appreciated.