Congrats! I don't know the answer to your question, but I had a similar one just yesterday. I looked out on my jade vine to see that I have several fruit (seed pods) set after this springs bloom. I thought we didn't have the pollinator here in Florida, but perhaps we do.
Makes me wonder if other non-indiguneous pollinators are afoot in our area.
Anyhow, enjoy your vanilla!
Keith