You can do a cross-grade and get just the Mac App, but depending on the version you have WMA or Audiophile, you will need to convert the wma to m4a to use it on Mac not sure if the BIAB2014 for Mac will support the wma files or not when it is released ?
The Audiophile files will work with BIAB Mac because it can use wav.
On the Mac you just need to rename BB\RealTracks\Library to
BB\RealTracks\LibraryM

There is also Boot Camp.