I have not heard more examples of corruption with the use of bitcoin. It will be difficult to do as most people don't know what it is and don't have the necessary amount of bitcoins. Besides, any action on the Internet are easier to track than Fiat.
How many cases of corruption with diamonds have you read in the news? Or with gold?
Bitcoin is used by far too many poeple to make it relevant on global scale but once it does you will see people getting their bribe in
BTC , it's just a matter of time.
And in a world that tends to get rid of cash and replace every banknote with virtual fiat and bank transfers,
BTC is actually the way to go.
You can track
BTC in the blockchain (although with a good mixer used time after time it will become extremely hard) but there is nothing that can link a person to a wallet or to an address.
You can't hide your bank account as god as you can hide a password to an address full of coins.