Pitch Bend Range (aka Pitch Bend Sensitivity) is set with RPN-0 + Data Entry for MSB/LSB. GeoShred sends RPN-0 with the MIDI Configuration's pitch bend range to MIDI out on program change
As of this writing, most synthesizers respond to RPN-0 and you essentially get automatic alignment of sender/receiver pitch bend range.
A Pitch Bend Range of 1 means that you can bend +/- 1 semitone
A Pitch Bend Range of 12 means that you can bend +/- 12 semitones
The MIDI Specification supports pitch bend ranges up to 24 max, and the current MPE proposal extends this to 96 meaning +/- 96 semitones
Pitch Wheel Change (aka pitch bend) is a 14 bit controller, with values ranging from 0 to 16383. It is treated like an signed 14 bit integer. No pitch bend means pitch bend = 8192, the smallest pitch bend is 0 and the largest is 16383.
pitchBendValuesPerSemitone = 8192/Pitch Bend Range
The sender and receiver will both use pitchBendValuesPerSemitone based on this calculation.
The MPE proposal calls out 48 as the default Pitch Bend Range. The Geo Shred MIDI Configuration Record-Playback uses this range as well since its channel mode is MPE