No,… even normal attack buff does not apply for minion,… here is explanation and analyst test, this post: Damage Calculation - #315 by Zack
I quote:
Now, for Glenda, it is more specific, so it very clear minion is not special skill that do damage.
Boldtusk does not help for minion, Glenda is also does not help minion.
One more again, here is sample Special do damage: Bane, Joon, Sartana, Magni, Sonya, Caedmon, etc etc… do direct damage, and clear text: Deals xxx% damage to enemies.