The problem is that RPM doesn't know that you installed wxGTK manually, so it's not installed for it ;)
Why don't you use the wxGTK package out of the extras repository ? Selfcompiling should be the very last option :!:
Perhaps you have to activate the repository, but the repository is preconfigured and usable by yum on every fedora installation. :)
One way installing wxGTK is opening a terminal (konsole/gnome-terminal/xterm/...) and running yum as root:
sudo yum --enablerepo=extras install wxGTK
This activates the repository only for this time. In graphical frontends like kyum or yumex should be a checkbox to activate the repository.