[PastaViking II]

Unfortunately, I believe PT handles all the tempo changes when Live is in Rewire slave mode. If I had to suggest a workaroud it would be to use Core Audio instead of Rewire and send audio into PT that way (with a cable). Start Live first to disable it as Rewire Slave (you need the full version to do this). Then slave PT to Live's tempo via the IAC bus.

Hope you get the idea - I haven't tested it myself...