There currently isn't a way built into JFBConnect (or our JFBCInvite module that's included) to add tracking information to invites. However, it's something we've helped other user's add, and can help you if you need it.
Basically, it would take just a few lines of code to add something like &ref=limedezign to the URL of the user that someone would visit after they've been invited, and, again, is pretty simple. This would not do the tracking itself, you'd still need something else to track those referrals, but I'm assuming you already have that setup.
Thanks,
Alex