Apple is larger than Samsung, and Is their biggest customer, so absolutely.
Apple is not larger than Samsung. It has higher market capitalization but Samsung is bigger in many categories. Quote:
Samsung, though, is already bigger than Apple in terms of revenue. It's forecast to report $137 billion in 2010 revenue, more than double the $65 billion Apple took in during its most recent fiscal year.
And Samsung spends 10 times more than Apple on R&D