Do you mean nationality-wise or ability-wise?
In terms of nationality I don't know if Luke was born in England or Australia, but he'd qualify as British because his parents are British (being the son of the former Belle Vue and Wolves second-halfer Frank Killeen - known as "Fearless Frank" or "Frank the Fence" depending on how he was going at the time).
In terms of ability, I don't know if riding in an Australian State Championship still allows him in the NDL on a 3.00 average. (presumably it must).