I have successfully followed the instructions for setting up 802.1q VLAN tagging in Fedora. Now I need to make sure that when I reboot the 8021q kernel module is loaded again.
Fedora, both methods will work, there is no guarantee to chose which one is preferable.
Redhat/Centos, you should use
/etc/sysconfig/modules, since when it's documented in Redhat documentation - Persistent Module Loading.
Another way you can use
Redhat/Centos base distro. If you use
Debian base distro, use file
/etc/modules file instead.