I think it’s a bit reductionist to say “similar mentalities”. They’re both authoritarian states, but that’s pretty much where it ends.

Putin’s Russia is all about reviving the Russian Empire and reliving past glories. China is capitalist through and through. They want to own world trade. As such they do not share goals, and if there is an alliance it will be a utilitarian one and probably short lived after it’s usefulness has ended.