I've never used a HWIC AP before, but I think you might have the wrong end of the stick on a couple of things.
Take a look at the following config and see what you think. This uses VLAN50 for the AP Management Address and VLANs 100 & 200 for client traffic.
interface Dot11Radio0
no ip address
no ip route-cache
!
encryption vlan 200 key 1 size 40bit 7 <> transmit-key
encryption vlan 200 mode wep mandatory
!
encryption vlan 100 key 1 size 40bit 7 <> transmit-key
encryption vlan 100 mode wep mandatory
!
ssid BMS_network
vlan 200
authentication open
!
ssid data_network
vlan 100
authentication open
!
short-slot-time
speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0 54.0
channel 2437
station-role root
!
interface Dot11Radio0.50
encapsulation dot1Q 50 native
no ip route-cache
bridge-group 1
bridge-group 1 spanning-disabled
!
interface Dot11Radio0.100
encapsulation dot1Q 100
no ip route-cache
bridge-group 100
bridge-group 100 subscriber-loop-control
bridge-group 100 block-unknown-source
no bridge-group 100 source-learning
no bridge-group 100 unicast-flooding
bridge-group 100 spanning-disabled
!
interface Dot11Radio0.200
encapsulation dot1Q 200
no ip route-cache
bridge-group 200
bridge-group 200 subscriber-loop-control
bridge-group 200 block-unknown-source
no bridge-group 200 source-learning
no bridge-group 200 unicast-flooding
bridge-group 200 spanning-disabled
!
interface Dot11Radio1
no ip address
no ip route-cache
!
encryption vlan 200 key 1 size 40bit 7 <> transmit-key
encryption vlan 200 mode wep mandatory
!
encryption vlan 100 key 2 size 40bit 7 <> transmit-key
encryption vlan 100 mode wep mandatory
!
ssid BMS_network
vlan 200
authentication open
!
ssid data_network
vlan 100
authentication open
!
speed basic-6.0 9.0 basic-12.0 18.0 basic-24.0 36.0 48.0 54.0
station-role root
!
interface Dot11Radio1.50
encapsulation dot1Q 50 native
no ip route-cache
bridge-group 1
bridge-group 1 spanning-disabled
!
interface Dot11Radio1.100
encapsulation dot1Q 100
no ip route-cache
bridge-group 100
bridge-group 100 subscriber-loop-control
bridge-group 100 block-unknown-source
no bridge-group 100 source-learning
no bridge-group 100 unicast-flooding
bridge-group 100 spanning-disabled
!
interface Dot11Radio1.200
encapsulation dot1Q 200
no ip route-cache
bridge-group 200
bridge-group 200 subscriber-loop-control
bridge-group 200 block-unknown-source
no bridge-group 200 source-learning
no bridge-group 200 unicast-flooding
bridge-group 200 spanning-disabled
!
interface FastEthernet0
no ip address
no ip route-cache
duplex auto
speed auto
!
interface FastEthernet0.50
encapsulation dot1Q 50 native
no ip route-cache
bridge-group 1
no bridge-group 1 source-learning
bridge-group 1 spanning-disabled
!
interface FastEthernet0.100
encapsulation dot1Q 100
no ip route-cache
bridge-group 100
no bridge-group 100 source-learning
bridge-group 100 spanning-disabled
!
interface FastEthernet0.200
encapsulation dot1Q 200
no ip route-cache
bridge-group 200
no bridge-group 200 source-learning
bridge-group 200 spanning-disabled
!
interface BVI1
ip address 192.168.50.9 255.255.255.0
no ip route-cache
!
ip default-gateway 192.168.50.254
bridge 1 route ip
