Air France offers "Seat Plus" and "Premium Voyageur".

Seat Plus is as described above on the 747: exactly the same seat and service as economy, but in an advantageous location on the plane (such as on the upper deck) and usually more legroom. This is roughly equivalent to E+. Elites can book Seat Plus, higher level elites for free, and others can pay a supplement at the time of booking or after to get a Seat Plus seat.

Premium Voyageur is a different class of product, a completely different seat, with amenity kit, etc etc. It has the same meal service as Y, but everything else is upgraded. No comparison between Premium Voyageur and E+. Also, Premium Voyageur has its own fare classes, elites do not get automatic access and you cannot simply pay a supplement to sit there.