It should happen that installing broadcom-wl pulls in kmod-wl as a dependency. I'm just not sure that it does.
yum install kmod-wl
and see what happens then.
If it doesn't work, post back the model of the card from the output of:
Be careful of jumping to b43. It covers part of the broadcom range while broadcom-wl covers another part. There appears to be one card that they both support though.