FYI
Would like to share what happened a while a go although I (because i already some chinese visa way back 2003) and my son (a 5yrs old) got through my wife were required to submit some docs. The problem is she doesnt have any job, anyway she was required to have sponsorship letter coming from me that i will shoulder all her expenses and that is why i am now processing some documents (bank cert, cert of employment, etc) attached to the letter. My wife will get her nbi clearance anyway its easy she can have it immediately on any nbi kiosk, im not so sure if the embassy wants to have a copy of our marriage certificate to justify that shes my wife :) (legal wife)

RE: VISAS TO MAINLAND CHINA
To all those FIRST TIME TRAVELLERS TO MAINLAND CHINA, aside from the usual requirements (app form, 2x2 pic white background, roundtrip ticket, hotel voucher), you also have to provide:

1)NBI Clearance valid for travel abroad (DON'T GIVE US PERSONAL COPY!!!)
2)Employment Certificate with details (if you have your own business, DTI and MAyor's
permit)
3)Company ID
4) Bank Certificate
5) SSS ID and contributions
6)ITR and Tin I.D.

For Philippine passport holders. MANDATORY REQUIREMENTS. For foreign passport holders, no need unless the consul orders you to do so. Remember, to ALL FIRST TIME TRAVELLERS TO MAINLAND CHINA. So even if you have a lot of visas from other first world countries (US, Schengen, Japan, Australia etc etc), if you havent travel to Mainland China before, you have to provide EVERYTHING.