Checked that study out.
Couple things: it's a hard topic to talk definitively about, but it looks like right around half the population has religious beliefs... however, is it really fair to say that China is not a secular country? Being religious doesn't equal not being secular - I can believe in the Christian God, but not believe that his laws should be enforced by the government.
Similarly, the Chinese government can allow a certain amount of religious freedom, and it does, but does that allowance mean the government is not viewed as separate and distinct from the various religious groups?