the only issue that will be a problem with the joint is if you tile over it. Tile is not very tolerant of flexing so if the joint were to move the crack can "telegraph" up into the tile. There are membranes to try and avoid this but I don't know there limits.
I would use glue and rebar, why not.
[FONT="Franklin Gothic Medium"][SIZE="3"][B]Everyone is entitled to their own opinion, but not their own facts[/B][/SIZE][/FONT]