You went the right way as the Win Audiophile version has wav files that can be used by MacBB also, but the WinBB I don't think can use the aiff mac files.
So for $79 you can do a crossgrade and get the MacBB app
"Upgrade from 2012 or earlier or crossgrade"
http://www.pgmusic.com/bbmac.packages.htm

All you need to do to use it on the Mac also is copy the drive or use the current drive (though it is always recommended to have a backup copy) or if you use that drive on the Mac just rename
bb\Realtracks\"Library" to "LibraryM" and bb\Realtracks\Direct Input\"Library" to "LibraryM" This will allow the Shots n Holds to work.
Depending on what version os x you are using if it has NTFS write to allow you to write to NTFS win drives,
you might need to rename the folders first on windows.
If you copy the drive use Mac as it will write to mac file system allowing you to rename folders and also run the MacBB app from the USB 3.0 Mac format drive.

Or use the money on Parallels Desktop for Mac and get more features on Mac and as mentioned earlier Realband on the Mac.