Ems - Yo-yo loach breeding, by all accounts, has not been documented in the home aquarium. Same thing with Clown loaches, and most other Botia.
As for the circling thing, mine do it all the time - I think it's just a "chasing" sort of thing they do, maybe territorial, maybe just some form of loach interaction. In any csae, mine are constantly chasing eachother, circling, twirling around, etc... very entertaining, but I'm sorry to say I doubt they're breeding.