If you have the proper applications and hardware to transfer files with bluetooth, it should work. I don't know of any options to sync your library by bluetooth though.
You will have to export the library on the source computer, and import it on the new computer:
Export the source iTunes library as an XML file (File>Export Library…). This will create a file that holds information about the location, song filenames, and *song rating*!
Replace the file paths in your XML file with the path that the songs from the source library will be in when you import them. This path may point to your FireWire Drive, a DVD you have burned, or a temporary folder on your hard drive that you have copied your music to. Just to be sure of the new path, copy one of the files from this location to your library, export your destination library, and look at the file path to that song in the resulting XML file. To actually replace the file paths, I did a Find/Change in TextWrangler.
Set the preferences in iTunes in your source library to “Copy files to iTunes Music folder when adding to library.” This is under “Advanced.”
Import your library (File>Import).
Delete redundant files. If you’re like me, you have some duplicate songs in your multiple libraries. This is a tedious task, but I plan to do it over time.