Terracotta is okay, but don't let that plant dry out! I've always kept my vanilla in a plastic pot ... until I was in the depths of despair and I might not have watered it very often.
I used a standard potting mix with added perlite and leca for my vanilla. (:
Thank you, that's where I felt confused because 50% Google said orchid bark and the other 50% Said chunky soil. And it came on a bamboo stake so I'm going to try and find something nicer... Would you say smaller pot to avoid root rot?