No, to quote Transavia website: "Transavia is not a member of the Skyteam and therefore does not offer the Flying Blue Elite advantages.". So no priority security, boarding, seat selection etc. However, there is a little exception when I booked a Transavia flight as KL codeshare. As it is an KL-coded flight, I did get a free hold bag on check in. The agent didn't mention anything when handing over the passport + FB Silver card. Although, before arriving at the airport Transavia and KL on Twitter denied this 'benefit' because HV isn't a member of Skyteam (and manage my booking doesn't reflect this free bag allowance'.