Is it acceptable to only use refererences from other universities?
It is certainly acceptable to not have references from your current institution, but it could raise questions, implying that something went wrong in the current position. Having trustworthy, high-quality researchers, as you've indicated, can overcome this problem, though the question still will remain. 

Your references do not necessarily need to be familiar with all of your work, just enough of it, and more importantly, how you are as a researcher and person. Having a more recent reference letter would give a better description of how you are performing now, in particular, after you left the safety of a PhD position. That is, how you are performing now that you've gone out into the world on your own.

My inclination would be to include a local reference for these reasons.