Rough-up the PLA a little with some sandpaper... it will improve adhesion.
'Dab' a little RTV Silicone Adhesive on the crown of the rim, and slip the Grifiti band on.
It will take about an hour before the adhesive sets.
Press the wheel (servo horn) onto the servo.
You could hook-up a servo tester at this point to make sure that the wheel rotates without wobbling.
When everything looks good, install the set-screw.