This AA also affects the AA skill Replenish Companion.
I verified this by casting Replenish Companion, and noting the recast timer (27 or 28 minutes or so). I then bought rank 2 of Hastened Mending, checked the timer (which had dropped to 17 minutes and some seconds), then bought rank 3, at which point my Replenish Companion timer was under 9 minutes.
Mage Kirrawur Flamedark on The Rathe (Prexus) (Karana)