I suppose they will control possession much better against Liverpool. Bayern are better on the ball than Liverpool which is why Real were pushed back. Don't underestimate the effect Anfield has on them as well. Playing in a neutral ground will be a different prospect especially when faced with a team that can pass it around for fun.
Anfield is obviously advantageous for them but to be fair they've also had impressive wins away at Porto and City.
Real will definitely have most of the possession but I feel like that's how Liverpool would prefer it anyway. They're at their best when they're playing on the counter attack, pressing from the front and harassing the opposition into mistakes.
I still can't look past Ronaldo v Lovren and Kroos & Modric v Henderson & Wijnaldum as being two areas where Liverpool just can't compete.