I've just used 2000 #DB BahnBonus points on a Freifahrt International ticket (Kolding-Munich with a minor 16 hr transfer in Wuppertal, return in Nightjet Minicabin!).
Maybe everyone here knew this already but it took me some time to figure out:
Booking a free BahnBonus Freifahrt only works (logged in or not) if the language on the bahn.de website is set to German..
Knowing DB this is probably not malicious but just a known issue on a very long to-do list.