Determine the Winner of a Game of Australian Football
Jelly, 3 bytes
ḅ6M

A monadic Link accepting a list of lists of integers, [[g1,b1],[g2,b2]], which yields a list [1] or [2].
(Draws would yield [1,2])
...Or a full program printing 1 or 2.
Try it online! Or see the test-suite.
How?
ḅ6M - Link: list of lists of integers, X
 6  - literal six
ḅ   - convert (X) from base 6 (vectorises)
  M - maximal indices