To nitpick, none of these was ever called Antares.
To nitpick further, none of these was ever indicated to be a Bajoran ship; the bottom design was hired by Bajorans, but indicated to be owned by Petarians, with a human skipper. It did happen to have a dedication plaque saying "Antares class", though. But off focus, and without dialogue to back it up.
Two designs have been referred to as Antares class onscreen. One was a Corvallen freighter ("Face of the Enemy"; recycled footage from "Outrageous Okona" IIRC) that was space dust by the time our heroes got there; the identification may have been incorrect, then. The other was indeed a Bajoran triangle-ship ("Ensign Ro"), but whether it was an Antares class vessel or a N'taaris class one, we don't know, because this time there is no written evidence.
That's all correct. The only ships we know of that were referred to by the name "Antares" (whether a class or a ship name) were the Corvallen and Bajoran ships (dialogue), the Xhosa (dedication plaque), the S.S. Antares (Charlie X, dialogue and CGI model for TOS-R), and the U.S.S. Hermes (Antares class from the ST Encyclopedia). I also seem to recall some muddled reference in the Encyclopedia about the Batris, but I don't think it was ever confirmed.
(There's also a U.S.S. Antares from Star Trek '09, but that doesn't count...)
BTW Timo, does the closed-captioning for "Ensign Ro" state that the ship is "Antares?" Because that would be some kind of evidence that it wasn't "N'taaris," or something else.