CORRECTION, it's not an "optical zoom". Optical zoom is what you have with your standard lenses, ex. 14-45, 45-200, etc. That's the actual optical (glass) zoom range of your lens. What you are referring to is the "digital zoom", and yes, it's only avail in jpg...but I would advise against using it unless you really NEED it and it' the ONLY way to get the shot. It degrades the image quality quite a lot. It's a gimmick really. It shouldn't really be included on any camera - except maybe on a cell phone where an optical zoom is usually physically not possible....IMO.
Thanks for the advice - extra optical zoom does not work in raw. Should have been a no brainer, but there you have it.
BTW I think that extra optical zoom is slightly different from digital zoom: instead of cropping the image, it works by only using the central part of the sensor, at the cost of resolution. Don't use it much by rule, but sometimes it's useful - e.g. if using a 50mm legacy lens and you want to get closer. In those cases I find it more useful than cropping, because it gives you finer control over what the camera focuses on (i.e. if you crop more closely, sometimes you'll find that the camera didn't quite focus on what you were interested in...)
Anyhow, the 6mp image that you get is normally fine for my type of work.