Do President Bush's new sanctions mean anything if Chinese companies are still allowed to trade with and support the Bashir government?

I doubt it:

Chinese companies have developed a reputation for going where others won't because of political, environmental or ethical concerns, or because profit margins are too slim. State-owned companies in China, analysts say, have the ability to forgo short-term profits in pursuit of the government's long-term strategic interests.

China's oil interests in Sudan run deep.