Why do you need wireless users on both vlans?
I have 2 wireless vlan because each has a different encryption and authentication method.
If you want that, you'll probably have to upgrade to a wireless access point that supports vlans. The Cisco ap's do. Or get a second linksys wireless access point and connect 1 access point to each vlan. Give each access point a different SSID. Also, make sure the channels don't overlap.