Yes this is the same set up as I use , made the code local arm /disarm keypads A house , B garage. You can arm garage bt pressing (area). b(2) and (yes) from the house keypad it will also stop the bells ringing if you enter your code in the house but not disarm the garage in an activation.
Can I just ask a bit of advise on this please, I have a very similar setup, Prem Elite 24 with 1 RKP in the house and have 1 zone protecting and wired to 2 x door contacts on a shed in the garden, I only access the shed approx. 2 times a week.
I have the zone programmed as 24 hours, when i need to access the shed i scan my tag, menu 9 then omit the 24 hour zone, to re-instate when finished I do the same. Is there any advantage/disadvantage doing it this way rather than how you describe above? cheers.