Obviously your A2 predictions are important as they're used by universities to give offers, but if your A2 predictions are a lot higher than your AS's, some universities might not trust you'll be able to improve so much if you don't have a valid reason for lower AS grades. Because of that, I'd say AS levels are more important. Plus, it's really important to do well in your AS's because then you don't have to work as hard to get the grades you want in A2, when the content is a lot harder and marks aren't as easy to achieve. Better to get all the marks you can at AS.