That's an absolute non-question. why would you even want to degrade your footage already when you know you are going to edit it further in Premiere. You need to read up on what "digital intermediate" workflows are. Retaining the best possible quality as long as possible is common best practice. There would be zero benefit of pre-encoding anything from AE, since even Premiere's smart-rendering will have to re-render stuff as soon as you change anything.
As Mylenium says, you want the highest quality you can have out of AE to use in Premiere. A digital intermediate will not have any quality loss at all (or nearly none). Cineform, which is native to newer versions of CC is a good choice - it's a pretty good balance of quality and file size. QuickTime with the PNG codec is technically lossless and a decent file size considering that.