Bass & treble should both be boost/cut, with the center detent as 0 dB (no change). Doing an A/B with the Precision makes both controls very apparent.
Truth to tell, I play my Bantams with both tone knobs cranked to 10, because it's just so nicely rich, then adjust at the amp. And I rely on the neck (well, middle) pickup because otherwise I'd stomp all over the guitars.
The bridge pickup, with Tone high & Bass low, made me curious about restringing it to play a little like Stanley Clarke's piccolo bass solos, but really not a tone I could see for general use. If I lost the bridge pickup, I wouldn't miss it much.