Hmm... next time you cld start a new topic and ask 
But anyway monkey king is worshipped by Folk Tradition Taoist, not
Buddhist. And yes, monkey god of Journey to the West (a fictionous
story) is fictionous. And why is the monkey god worshipped? no idea
too... to me, such practices derived from superstitions.
from Global Moderator, Henry of E-Sangha forum:
from what i know, Hanuman, the Indian monkey god, is also brought
into China thru the Silk Road. however, this monkey god played no
significant role in Buddhadharma, just a minor god.
the Japanese NHK expenditure team discovered a small figure of two
hugging monkeys in a Buddhist stupa ruin at Khotan (He Tian,
Xinjiang province) 20 yrs ago.
as for the cult of Sun Wu Kong in Chinese temple, including
Singapore ones, is the same fictional Sun Wu Kong from Xi You
Ji.