Mr.balbacal, do you have a Vietnam work permit or Vietnam residence permit? if you have one document, you can have a try to apply for your Chinese visa in HCMC, otherwise, you have to return to Philippines to apply for it. It will takes about 4 working days if you can provide all required documents. You can send a person to apply for visa for you. If you apply for Chinese work permit, the following documents are required:
1.Applicant's passport with blank pages and at least 6 months validity left before expiration.

2. A truly and completely filled application form affixed with one passport-size or 2x2 colored photo, with white background, full-face front view, and no hat. Photo must be glued on the application form. Stapled pictures will not be accepted. Scanned photos will also not be accepted.

3. An original Visa Notification Form issued by Chinese authorized unit.

4. Alien Employment License of the People's Republic of China issued by Ministry of Labor and Social Security

5. All working visa applicants shall provide a Physical Examination Certificate for Foreign Citizen (physical exam forms, guidelines and list of accredited hospitals are available at the visa counter).

6. All Philippine passport holders who will go to China for the first time must submit an original NBI clearance valid for travel abroad.

7. The emergency contact information page in the applicant's passport should be filled out and photocopied.