What does The Travels of Marco Polo tell us about religion in China at that time?

Marco Polo was in China for almost two decades. This was during the rule of Kublai Khan, the Mongolian emperor and grandson of Genghis Khan. During his time in the Mongol Empire, Marco Polo studied the various cultures that made up the citizenry as well as foreign traders.
During that time, China did not have an official religion, but Buddhism and shamanistic practices dominated as common belief systems. In the book, it is evident that Marco Polo saw a melting pot of cultures and religions. Kublai Khan's financial administrator was a Muslim. The Muslim population was very much represented in the Mongol Empire, as was Christianity. In the book, it is evident that China at the time was a mixture of Far East and Near East (a.k.a. Middle East) cultures.