Russia selling gas to China is completely orthogonal to Nord Stream issue.

The strategic win in bombing Nord Stream was that Ukraine finally got Europe on their side. Before NS was blown up many countries, especially Germany were sitting on the fence, reluctant to give Ukraine any help. They were hoping for Ukraine to lose the war quickly, then they would give Putin some slap on the wrist punishment, and return to "business as usual" with Russia. Nord Stream being destroyed removed the biggest incentive for doing that.