For vacuum bagging, you place the laminates in a bag without a platen (with breather mesh to allow the air to evacuate), draw the vacuum, then bend the assembly in the bag around your form. You need to clamp the bagged assembly around the form. It's best to have a polyurethane bag as opposed to a vinyl bag as they are more flexible. Adrian Ferrazzutti showed us this technique for another student in the workshop I did with him at Anderson Ranch. It was cool.

Personally, I think I'd go with the caul approach Michael Fortune used in the slide I posted above...

Mike