Assuming the holographic system uses voxels, it would need to be capable of displaying 108,900 (330x330) voxels per cubic inch to allow the same level of resolution as an iPhone 4 if it produces a flat surface. This would allow Retina-quality images when viewed from at least 11 inches away.
Assuming also that one voxel is 32 bits and not compressed, then the hologram would be 435,600 bytes per frame per cubic inch. At 24fps (you did say "film") that's 10,454,400 bytes per second per cubic inch.
Let's say it projects a hologram to fill a room the dimensions of a Star Trek-style holodeck, a cube of maybe 10 metres on a side. That's about 400 inches on a side, or 64,000,000 cubic inches. That means that a holographic film would be 669,081,600,000,000 bytes (608.5 terabytes) per second.
So, to answer your question, a 2 hour holographic film would be 4,817,387,520,000,000,000 bytes (4.178 exabytes) in size.
Yup, there's surely a ton of ways to compress that. Occlusion culling would be one, since you'd never see the insides of objects. For another, modulo atmospheric effects like fog and smoke, there'd be a lot of empty space between objects that even run-length encoding could compact quite a bit. I'm sure that even with lossless compression you could get it down to the petabyte range.
