At the end of rpm build scripts are run to automatically add requires and provides that aren't explicit, it happens for a lot of languages. If you think it's wrong the you can tweak your spec file to override these scripts or specifically exclude things you know if will get wrong.
In this case you'd want to use the __requires_exclude filter.
P.S. if you are compiling your own perl simply to get a newer perl you might look at software collections, which includes perl 5.16 http://wiki.centos.org/AdditionalResources/Repositories/SCL