Neither a BTA nor a "sebae" are natural hosts to ocellaris. I bet they would take to a ritteri, gigantea, or mertensi pretty quickly.
Having the appropriate host species is much more important than WC vs captive bred. That being said, anything can happen in time, but ocellaris using a BTA as a host is a combo that seems to generate a lot of frustration.
BTW, forcing a clown into a nem is generally not recommended since it could result in the clown getting stung. That might not be a large risk with a BTA, but could get ugly quick with one of the carpet species.