There is a bug in auction items.

Demonstration:
GAME 1449
We (Russians) were invading Americans and the Knight Templar auction turned out.
I got the highest bid and won it, however it remained active for the previous owner - a player in American Territories.
Now, during the battle, there was another auction - Court of Camelott.
When another player won it (not a member of either civilization) it activated Knight Templar for my troops.
I think there is a delay of one - the player who won the auction will get his reward as soon as some other player wins another auction.

Was I clear enough ?
Someone can confirm ?

Thanks,
Pawelo

CivWorld Wiki :

Knights Templar

The winner's defending Military Units are doubled, up to a maximum of 10 units per type.
This refers to units currently in a battle on the defender's side.
If the winner is not in a battle or is the attacker, the auction will have no effect.

There's no reward delay when you've won an auction.

Okay, thanks,

It seemed to me just that the bonus occurred late in the battle.
Anyway, case closed.

I've tested the Knights Templar and as the defender every filled slot had 10 more units. :)