Mark Brazil's Birds of East Asia says there are between 10,000 and 1,000,000 breeding sparrow pairs in China today (well... in 2009 which is pretty close to today).

That suggests two things. First, no one really knows how many sparrows there are in China. Brazil's estimate covers three orders of magnitude. That is no way that a reasonable range band for anything that is more than an educated guess. Second, the sparrow population is a tiny fraction of what it was before the "four pests" program. Estimates are that up to a billion sparrows were killed in the program. Even a million breeding pairs, would only be a fraction of 1 percent of the pre-program population.

Given numbers like these, it's pretty hard to say anything other than, no the sparrow population never recovered.