So if you use mind control on someone with perplex and use the action from mind control to use the perplex when dose the bouns from perplex go away?

It "goes away" at the beginning of the Mind Controllers next turn (assuming the Perplex isn't countered or lost before then).

At the beginning of the Mind Controlling character's force's next turn.
Or when the Perplexed character is healed or damaged.
Or when the character that used Perplex loses Perplex.