https://collections.accor.com/

Takes 2 months to credit from the date the transaction shows as pending, which occurs more or less reliably depending on the merchant (0% for groupon, 100% for itunes in my limited experience). If not an Apple user, I recommend ordering a cheap doodad from aliexpress (about 80% success rate on over 20 orders here) on the French website (merchant was removed from US website last week), e.g. a >$1.25 charging cable with free shipping.
If you use the US site, beware that it appears ALL actually credits 1 point per €, not per $, despite the posted rate.

Once you get the 'Your x Points are on the way' email, points reliably post in almost exactly 2 months, 2 days after you get the 'You've collected x Points' email.
If no email within a few days of the transaction, it was not registered properly. Temporarily authorizing all cookies, disabling adblockers etc. helps.