The report reveals that 60 percent of iPhone users—or at least, those who were polled—spend more than $100 per month on their plans. Above that, 10 percent spend $200 or more—and only 6 percent spend $50 or less. Compare that to Android, where 12 percent pay less than $50.
So, why do iPhone users spend more? It's almost certainly down to the fact that, through necessity, iPhone users tend to be on more expensive data plans to begin with. More here.