In my opinion, they won't be able to track your income unless declared. Cause if Bitcoin is a system that can be tracked by centralized authorities like banks and government, where's the sense of it being decentralized.
They may or may not be able to track your incoming funds if they are in the form of Bitcoin. But the moment you convert your coins to fiat, they will be able to track you (unless you are selling your BTC for physical cash without any ID verification). So be careful about it.