Is Taoism the yin and Confucianism the yang of Chinese religions?
Where does the third great religion [Buddhism] come in then? You are mixing a religion and philosophy. In all truth most people today only inherit the philosophical viewpoints and call themselves members of these schools of thought.
Taoism is the relation of things to each other and how there is balance, Confucianism is the relation of people to each other. They both contribute to chinese thought, and to label Confucianism as a religion is incorrect, because it is not a religion, just a way to act. My answer is thus, no they are not the yin and the yang of Chinese religions because they are not one and there are more than two religions
Taoism is not a religion, but a philosophy.
Despite opinions to the contrary more often than not offered by non-Taoists, Taoism is not the corollary of Confucianism, nor its opposite, nor in a dualistic relationship with it. Taoism is anti-essentialist, non-proscriptve, and exceptionally good for thinking with. It is not a set of rules for thinking or experiencing the world or the Tao itself.