Aye but if its not freestanding then my preference would be the bath going in first, just remembering to cover it so it doesn't get damaged by any tiles. It's a bit chicken and egg really and there are pros and cons to both routes.
Just make sure you fill the bath before laying the tiles, grouting/sealing, so the bath can sink (as it will with all that weight in it).
If you grout and seal properly you don't need overhang.