Can I isolate a onewire device using a bidirectional serial isolator?
Due to the complete lack of responses I ordered some parts and built my own test circuit; using a TMA1205S isolated DC-DC converter, an ISO1541 and a DS2401. I connected the onewire bus to the SDA pins of the ISO1541, gave each side the requisite 5K1 pull up, and it appears to work fine.

So the answer is yes, you can use a bidirectional i2c isolator for onewire isolation. This works out well for both my BOM cost and development time.