If you are using gksu from our repo I'm very puzzled. I built that waaaaaaay before 5.9 Standard went gold. So there was no chance of KDE deps getting pulled in.
As far as your sudoers file goes, you must have the command that is going to be used (full path) in the WIFI command group.
And to launch the command as normal user you need to call it like so:
You'll need the full path since vwireless is only in roots path.