Every government, at least in the Cold war era (and assuedly in fallout's where nuclear war was believed to be imminent) has a "Continuity of operations" plan, so did they have some sort of organisation designed to emerge post war? Almost certainly.
However, Given that China's political structure is very different, I dont think there would be a need for a shadowy enclave style organisation. I think any "Chineese Enclave" would be able to trace its link directly to those in the official seats of power when the bombs dropped.
However, there isnt really anything in canon that tells us whats is happening in china.