Not necessarily to very unlikely is the only answer I can give - vanilla marigolds are F1 hybrids, and they either don't produce seed, or the seed they do produce is variable if they're not isolated together, away from other plants. If you've the space to grow them from seed, you could give it a try to see what you get.

Depends somewhat on whether they were cross fertilised with another variety. Don't know for sure with F1 hybrids.
Try it and see.

Oops sorry Bamboo, we crossed up.

I tried to grow some seed from a Vanilla one,but sorry to say they didn't germinate at all,but you may be luckier than me..

Bloomer, I did the same as you from last year's flowers. Not a sausage!!. This year I have the yellow and orange african marigolds. Will give it another try, but not hopeful!

Nothing ventured,nothing gained..so worth trying :o)