The text description for VR and rigging on page 266 in core would seem to indicate the rigging bonus for VR is in lieu of the standard matrix VR bonus.
As usual specific trumps general, with the rigging rules noted below being specific and the matrix rules for VR being general.
If they wanted riggers to get both bonuses they would have said it right here.
Instead they indicated a different initiative and dice pool bonus without reference to the standard +4d6/+2 VR matrix bonus.
So if you are arguing that the +2 VR matrix bonus stacks with the +1 rigger VR bonus than you *must* also be arguing that the initiative bonus should also stack (+4d6 for matrix VR, +3d6 for rigger VR = +7d6 <max 5d6>).
So clearly Aaron was smoking something when he wrote his response and clearly the rules as written indicate the rigger VR bonus is different from the Matrix VR bonus.
Given Catalyst's horrific track record on editing/ composition/ writing of rules I'm guessing what happened here is that one person wrote the section on rigging and a different person wrote the section on decking and they didn't end up comparing notes.
So the riggers were meant to get the same bonus from VR as deckers (+4d6/ +2) but instead they got different bonus because the line editor is out to lunch.
I think this is the case because the first paragraph below indicates riggers should get the same matrix bonuses as deckers.
This also makes sense in the situation where a decker is acting in hot sim VR then jumps into a drone/ vehicle.
If you presume the same bonuses for riggers and deckers nothing changes, initiative remains the same.
If you follow the rules as written you must re-roll initiative after you jump in, which seems dumb to me.
So at our table we're going to houesrule that riggers get the same bonuses for VR as deckers and call it a day.
It's more sensible, more elegant and removes any confusion.
<edited to remove rhetorical comments>
See text below:
VR AND RIGGING
When you’re jumped into a vehicle or other device, you’re in Virtual Reality mode. The control rig allows you to treat Vehicle actions the same way you treat Matrix actions, so any bonus you get to Matrix actions also apply to Vehicle actions when you’re jumped in; this includes Vehicle Control Tests, Gunnery Tests, and Sensor Tests.
Just like in the Matrix, you have the option of using cold-sim or hot-sim while rigging. If you’re using cold-sim, you get +2D6 to your Initiative (3D6 total), and any biofeedback damage you take is Stun. If you’re using hot-sim, you get +3D6 (4D6 total) Initiative dice, and a +1 dice pool bonus that applies to all Matrix test (in- cluding Vehicle actions), but all biofeedback damage is Physical damage.