Hello Tim,
The missing program is not part of Bibledit-Gtk, but part of the Sword library.
If osis2mod is not in package libsword, then it should be in libsword-dev.
Trying this from the command line:
$ osis2mod
The program 'osis2mod' is currently not installed. You can install it by typing:
sudo apt-get install libsword-utils
Okay, I was mistaken, it should be in package libsword-utils.
Regards,
Teus.