Civilized vs Barbaric

One approach involves an order based on a sense of fairness, the other, a free for all:

"In their cultures, they do not queue for buses where they live and there is a scrum every time a bus turns up, while in British culture there is a nice orderly queue."

But if the cultural relativists are correct, and are to be taken at their word, aren’t the Brits dominating and subjugating these foreign students with their “fairness”? How do we know that this "fairness' principle should have universal currency between both Brits and foreign students with all things being culturally equal?