I'm getting the same surface finish when I vac bag my wet layup.  The effect (on both our items) looks like the resin is being drawn away from the surface.  I am having issues getting my bag to seal properly which means I have to keep the vac pump running until the part cures - I use a "hot box" to help things along.  I was wondering if leaving the pump running and pulling vac ( I get around 28 - 30 inches depending on sealing issue) for that long is causing the issue.

Are you able to seal your bags and keep vac with pump off till part cured or do you have the pump running all the time?