Advise whether there are intercity buses from bao'an airport to Taishan, Guangzhou?

There is no direct intercity buses between the two places.
You can take the airport shuttle bus 330 to reach it terminal, Luohu Railway Station. Then you can ask the local people to find Luohu Bus Station where you can find buses for Taisha. The buses for Taishan operate from 07:50 to 19:50 everyday.