Are XP training bonuses retroactive?

[Big J Money]

I guess there are two ways to interpret my question. I'm curious either way.

But what I really mean is, if an encampment trains a unit, and I later build a barracks, does that unit now have the 25% bonus to future XP gains?

 

[Promethian]

Nope. I also haven't been able to find a way to give the bonus to an existing unit. I'd really like for there to be an option to put a unit on an encampment and spend a turn plus a gold fee to give the bonus.

 

[Big J Money]

I don't know if this is related but once I brought one of my units into my own borders and I saw a +17 XP (or whatever) pop up over its head. It wasn't attacked. I never did figure out what that was about.