In RHATO #8 there's a flashback of a meeting with Tim and Jason exchanging information. While Jasons' flippantly refers to Bruce as "dad" Tim drives the point home on Jasons' connection to him.
Jason Todd: Hiding in plain sight. "Dad" would be so proud.
Tim Drake: Technically he's not your dad anymore. Not since you were declared legally dead, anyway.
I don't think that's correct from a legal stand point, you might not legally exist but you'd still be considered someones' adopted kid. But anyway if Dicks' not a ward or adopted then this still means Jason was the first bat kid Bruce adopted. On three different earths too.