The bridge supports only one SSID. You should assign the SSID to the native VLAN
1.Create subinterfaces on the radio and Ethernet interfaces.
2. Enable 802.1q encapsulation on the subinterfaces and assign one subinterface as the native VLAN.
3. Assign a bridge group to each VLAN.
4. (Optional) Enable WEP on the native VLAN.
5. Assign the bridge's SSID to the native VLAN.
To assign an SSID to a VLAN and how to enable a VLAN on the bridge radio and Ethernet ports
For further information click this link.
http://www.cisco.com/en/US/docs/wireless/bridge/1400/12.3_8_JA/configuration/guide/p38vlan.html