Well, Nightwing leaves no doubt at all that Bruce is in denial. The Joker knows that Nightwing is Dick Grayson. There's no room for any uncertainty in this.
I haven't been reading this, but I have been following this debate. If the Joker was only pretending to know various identities, wouldn't he be likely to assume that Batwoman was part of the extended family (ie, guessing that all Bat-people were part of a single group)? That Batwoman is not a target implies that Joker knows she's not a part of the family he's trying to destroy.