As I have read from some websites this wireless card takes a while to respond after hiberation. When using the proprietary driver from Broadcom it takes a minute for the wireless to come back up. I doubt, though, you're using the proprietary one.
Check to see what modules are listed. Use the "lsmod" command to check and see for the proper wireless-related drivers ("wl", "b43", or something like those). Check to make sure the modules are in place before and after hibernation. If the driver is missing then load it again with the "modprobe" command. You can also reload it by first removing it with "modprobe -r" and running "modprobe" again.