I currently live in NYC but am originally from HK. Been in NYC since Nov 2016. I did provide bank account details to AMEX for the opening of both the Plat and Cent, because they asked for it, and I’m happy to do so since I think it tends to improve one’s chances if there’s some money in it.
I’m not sure why some people claim that they are big spenders and haven’t been picked up by the system yet (sometimes, authenticity of such claims is dubious), perhaps it’s also a matter of many other factors. All I can say is I got it after 6 months of high expenditure, and that it isn’t related to any business spending. And from my experience, the two factors determining your chances of getting the Cent is 1) high expenditure (min. 250k USD++) and 2) strong financial status in your bank ac [and decent credit rating, but not of paramount importance I guess]