nkob/kees: Please review the terms and conditions. You can earn Accor points when flying KL, AF or A5 (Hop). Transavia is not included for earning, which also applies to all other Skyteam airlines.
If you stay with Accor you will earn Flying Blue miles. Those you can use to redeem for Transavia flights if you wish.
Somewhat offtopic; Buying luggage with AF/KL is priced exactly the same, irrelevant if you booked with miles or not. However when booking with points you get the first piece of luggage for free, so the second piece will be priced as a second-piece of luggage (Which is more expensive than when you have to pay for the first piece).