Do not worry. I live on Jubilee at the moment, and study Management with French; thus, half of my degree is based on uni park, and half jubilee. It does not affect you really though, as you can just get the hopper bus, and you'll be there, or do the 20minute walk over to Clive Granger. There are plenty of people who study on main campus that live on jubilee, I'd say around half of the hall is jubilee, and half of them study on uni park.
With regard to St. Peters Court, that is fine too, as instead of getting the hopper bus; you can just get the St. Peters Court bus instead, which takes you straight to the main campus. Not sure if that costs or not, I do not think that it does though.