I just noticed this today while poking around the website. Interestingly, I am a business owner and have a SkyBonus account that is linked to my individual SkyMiles profile. I also have a DL Business Amex for the same business.
This field was set to "No" for me, though. So there clearly isn't a feed back from SkyBonus - I'm curious if anyone else has figured out exactly what it does.