If you can make an automatic insertion of the BASS docs into the POD of your module you could duplicate the data. But if this can't be automatic you should just point to an URL.
In your POD you could add only some simple example, or informations about what is the module and some differences between your interface and the BASS interface, since they are in different languages. You says that wxPerl don't need POD, well, it needs, not about the classes that it wrappes, but about the way that it wrappes.
Graciliano M. P.
"Creativity is the expression of the liberty".