Good replies. A bearing as they say is relative to you. The bearing, as said, is measured in degrees and can refer to almost anything, be it a beacon, an aircraft, an airfield etc.
VORs have radials and are therefore giving directional guidance and NDBs transmit a non-directional signal which enables you to work out the bearing to the beacon. Most people then use that to state they're on such and such a radial from an NDB. It makes it easy to think of it that way and it appears to be depicted that way on the charts.
A neat trick when tracking an NDB in an aircraft which has an RBI rather than an RMI is to forget all the numbers that are on the RBI and simply transpose the needle from the RBI to the DI. Also forget the RBI has a bottom half and just use the top half. This way you only see the head or tail of the needle in relation to your own heading. You'll be amazed how close you get !