How can I see if an OS X install disc is compatible with the computer I'm installing on?
Here is a complete list of all OS X versions and builds included with Mac computers. To get the build number of a DVD check the /System/Library/CoreServices/SystemVersion.plist file that is on the Install Media.

The string value for the Key ProductBuildVersion is the information you are looking for.

Now you can either check all of the bundled DVDs for the proper build number of your Mac Mini G4 or you can hack any of the DVDs (which potentially could be installed on your Mac) and include your machine in the "allowed" targets.

As an alternative you may "search" for a proper retail version.