For your wife's convenience, you may want to consider running her USB cable up through the hole in the base of the seat for backrest mount and then up into the bottom of the pouch.
That way the charging cable is in front of her, and she can use and charge her phone at the same time, and also charge her phone while its stored in the pouch. Doing so means there's no cable wrapped across her, or struggling with trying to get her phone back into her jacket pocket.
Even more important, if she has a phone case with a "pop-up" or a foldable "ring" on the back, before you begin a ride, she can either tie the cable into a simple overhand-knot around the pop-up, or thread the cable through the ring, and then there's no chance she can drop the phone and have it crash to the ground while you're driving.