oh no!! this is very wrong information!! Taiwan is NOT part of MAINLAND CHINA> Mainland CHINA is a soverign by itself. It's 2 different permits.
If your POA is Taiwan, then you do not need to apply for overflight Taiwan but please study carefully. Merlinxx is right! .use Jepp, UV, or whatever. they got the contacts!
and if you are landing in Taiwan or Mainland China, e.g, if your POA is Guangzhou ( ZGGG ) please use Hong Kong or SHengzhen as your alternates, avoid using say Taiwanese airports though they may be nearer.
just my 2cents.