http://www.chinaconsulatesf.org/eng/lszj/zgqz/
A foreign citizen who is transiting through China by air is exempted from a visa if he/she will stay only in the airport for no more than 24 hours and has
a valid connecting ticket with confirmed seating on
an international flight.
Citizens with passport or other international travel document, confirmed interline ticket and valid visa to the third country or region (if required) of the following 51 countries , can apply to
stay in Beijing, Shanghai, Guangzhou, Chengdu,Chongqing, Shenyang, Dalian and Xi'an without visa for 72 hours on direct transit via Beijing Capital Airport, Shanghai Pudong Airport or Hongqiao Airport, Guangzhou Baiyun Airport, Chengdu Shuangliu Airport, Chongqing Jiangbei International Airport, Shenyang Taoxian International Airport, Dalian Zhoushuizi International Airport and Xi'an Xianyang International Airport.
From the website of Consulate General of China in SF, you can only connect with a valid connecting ticker on an international flight. And the Wuhan - Guangzhou flight is clearly not an international one. And you can get a 72 hrs transit visa at the airport in other cities like Shanghai, it should not allow you to travel to other airports and leave from there.
And Priceline will definitely mention that it's travelers' responsibility to make sure that they have necessary travel documents for the journey.