All manufacturers have their own installation guidelines. I deal a lot with Coretec which is a vinyl plank product with a cork backing. Their installation requirements state that you will need to check your subfloor with a 10' straight edge for any dips or humps. Any dips or humps greater than 3/16" must be addressed. Humps will need to be ground down and dips will need a floor patch or self leveler. Home Depot sells a self leveler by Custom Building Products, this is a great product that I use on our jobs. If you choose to lay a moisture barrier (we don't with Coretec) the 6mil product you have shown named Blue Hawk will work.