I'm not sure if this would work, but EdiMarker can export markers in an AAF. I'm just not sure if Premiere would read these markers from the AAF. If so, you could export the markers from Pro Tools as a text files. You'd need to edit this text file so only the marker lines are in it and then you'd be able to import that into EdiMarker to export the AAF.
https://www.soundsinsync.com/products/edimarker