Originally Posted by
hhdl
You can credit future Delta flights to earn Flying Blue miles.
You can use (subject to availability limits) SkyMiles to book AF flights through Delta.
You cannot transfer miles between SkyMiles and Flying Blue.
You can also use Flying Blue miles to book awards on Delta flights through the Flying Blue website. If you fly enough to earn status, having Flying Blue status will be somewhat less valuable than Delta status when flying on Delta flights. But if you only fly enough to make it to lowest tier of status, it won't really make much difference either way.