Most time lapses that "Zoom" that I've seen were done with DSLRs at resolutions higher than video... i.e. 3000x2000 or higher. The images are then pan-'n'-scanned, or given the old Ken Burns treatment (i.e. zooming in post).
Depends on how long the shot needs to last... I would use an AC motor that drives a clock face, and somehow put a pully or some gears, foam wheel? to the zoom ring.
I once taped a still camera to the top of one of those on-off timers, it slowly rotated , turned lights on and off as needed, I got a most wicked 24hr time lapse of my front street.