Fiona used to have what I think was a scar on the back of her neck where no hair ever grew. It could also be just a molt. I'd keep an eye on it for changes like you mentioned, redness, inflammation, etc. but if it's just a small bald patch and Chipotle doesn't suddenly have a bunch of others, it's probably nothing to worry about.
Does she live with another bunny? That other bunny could be overgrooming. Especially that spot, they always lick there since they can't reach it themselves.
im definetly going to keep an eye on it and no chipotle lives alone and i have checked for fleas no sign of them hes had it for a while it hasnt grown or gone to other places and what exactly is molting