No, Tactics Ogre is not related. They share similar themes and stuff, but it's a different world. All the things Bolivar said are just wild mass guessing - none of that has ever actually been stated as canon.

And when it comes to TA, I'm pretty sure I read somewhere that St. Ivalice is the farthest future of Ivalice we've ever seen and the imaginary Ivalice is based on the land's past. Which would explain why Luso gets to go the real Ivalive of the past in TA2.