Maybe the mirror your installation is using hasn't synchronised yet. This one:
certainly has it.
There are three possibilities I think.
1. Wait until your mirror synchronises.
2. Edit your rpmfusion non-free file in /etc/yum.repos.d to have that mirror hard coded in.
3. Forgo the akmod variant, which requires quite a lot of dependencies and download the three packages for plain kmod-wl. Then use "yum localinstall" to install them.
I suppose there is a fourth option in that if you use "yum clean all" it will force yum to start again and maybe you'll get lucky with a different mirror.
If you go for option 3, and want more details, post back and I'll look out the notes.