With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cd11IfVlanId
Cisco DOT11 Interfaces Vlan Id
1.3.6.1.4.1.9.9.272.1.1.1.9.1.1
This object identifies the VLAN (1 to 4095) on this radio interface. The object value should match the corresponding cwvlWlanVlanId in the cwvlWlanVlanTable or cd11IfVlanSecurityVlanId object in the cd11IfVlanSecurityTable. When the value is '0', the encryption keys are applied to the non-VLAN configuration.
Back to CISCO-DOT11-IF-MIB MIB page.
IPHost Network monitor allows you to monitor cd11IfVlanId on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.