You can apply for China work visa from Chinese embassy/consulate in Thailand, the work permit should be processed by your employer in China, you can't process it in Thailand, I guess that you confuse the work permit and work visa.

Please pay attention to your Visa Notification Form, if it is written you need to go to China embassy in Bangkok to apply for visa, you can apply for work visa in Thailand, if it is written you need to go to China embassy in Manila to apply for visa, you have to return to Philippines. The Visa Notification Form and the Alien Work Permit should be offered by your employer, which are very important documents for China work application. If you employer can't porvide them, then you need to be careful, your employer is not authorized by Chinese government to employ foreigners.