Working out the naming of brain regions has been an annoying issue for me. Each researcher seems to feel the need to name everything from scratch.
As far as just the V1 through V6, wiki has a nice entry on this:
One of the confounding factors on the visual cortex is that it splits up into the WHAT and WHERE streams and these two pathways do not exactly match in terms of both location and connectivity.
I did a write-up on this topic earlier which prolly goes into this in more depth than you were looking for here:
As far as the 2 bits per synapse question; I an not sure what Jeff was trying to convey so I will pass on answering that.