I'm not finding anything for that specific model year, but this is what I found and it might work. It's worth a shot before trying to go through the dealership.
"Put the iphone Bluetooth into search mode.
Tell the car -by pushing phone command button on wheel to Pair phone
Car tells you to put phone into search mode and then type 1 2 3 4 as the bluetooth code.
Phone will see the car - will list as Aston Martin. Put code in
It will then fail! Car says pairing failed.
But you now have the iphone recognising the Aston Martin bluetooth, so on the phone, select "Aston Martin" on the bluetooth menu. It will bring up the boxes to put in the passcode. Put in 1 2 3 4, but do NOT press pair on the phone yet.
Tell the car -by pushing the wheel button to pair phone. Then immediatley press the Pair button (top right) on the phone.
Should then pair"