I have the same bag but a different front rack, and don't have any problem with cable routing. I route the cable under the rack, inside the bag loop in the front, under the loops in the back. My bars are not angled as much as yours, so the shift cable does not have the same upward sweep.
I would suggest using longer cable housing and attaching it to the rack with a pair of loose zip ties on each side. This will allow the cable to slide through when you turn, without putting a strain on the bag straps.
I don't have a good picture, but here is my setup:
