Well, after some investigation, I have not been able to get RB to work under Linux, at least in terms of actually connecting to the hardware, but I know why.
As a Windows application, RB needs to be run under Wine (Wine Is Not an Emulator, a recursive acronym) and currently Wine does not support USB devices in any comprehensive manner, so until Wine can be made to see the USB endpoints by creating an interface to the Linux libusb libraries, it isn't going to work.
Someone has managed to get an SBS-1 to work under Linux, see
http://oh7lzb.blogspot.com/2008/01/running-sbs-1-basestation-on-linux.html for details, but that's because BaseStation can be persuaded to connect to a network port rather than USB, I don't think RB can do this.
So, one day perhaps I can get this to work, but it seems not for the time being.