[cypher]

Any mould is worrying & can cause health problems but it doesn't sound as though it was a large area or there for long so it should be fine now it's been cleared away.
Can you put something under the bottle to catch the drips? When I used bottles I always put a little saucer of some kind underneath, either that or keep the bottle on a shelf so you can just wipe up any water that leaks or drips.