Hi! I answered this question this morning for you, but I am not sure how my answer disappeared and the other expert's answer is here! However, I don't think that your question was answered. .
If I understand your issue correctly, you are not asking about how to file your US tax return, but rather are asking if purchasing a house in China will be an issue if you failed to report your bonus income on both tax returns. Is this a correct summary?
Let's look first at the US side. As a US citizen, you are required to file a tax return for EVERY YEAR you work, regardless of the location. So while you may have to amend the prior two tax returns to report the bonus, you also need to file for the two years that you did not file at all. I don't think you will owe anything, though, as the Foreign Earned Income Exclusion allowed under IRC §911 of the tax code allows foreign wages, including bonuses, allowances, items provided on your behalf, and reimbursed expenses to be excluded. The Exclusion amount is increased every year, ranging from $91,400 in 2009, $91,500 for 2010, $92,900 for 2011, $95,100 for 2012, and $97,600 for 2013. So reporting the full wages won't have any effect on the taxes you pay in the United States. By not filing, the IRS can assess their own tax, and can disallow the exclusion if doing so results in a greater tax than just using Foreign Tax Credits (the Chinese tax you pay). They can also assess penalties and interest on the underpayment.
As far as the US finding out about you purchasing the house, I do not see any way for them to find out. It is not reported anywhere. There is a box on the Form 2555 that asks what kind of housing you live in, and you would check "purchased house or apartment", but it does not ask for any other information such as date, cost, etc., so from a US standpoint, this is not an issue at all. They can't seize your Chinese home!
From a Chinese standpoint, this is a totally different issue. One of my clients is an international construction company. They had a contract in China several years ago, and used a scheme called Offshore payroll. They paid the workers in Australia, and only paid Chinese tax on the amounts of money that were actually paid in China, which was a very small amount. The Chinese found out, and jailed (without trial or any judicial proceedings) the project manager until the company paid the proper taxes due, plus a huge penalty. So your not reporting the bonus to the Chinese could lead to huge problems, and may result in the seizure, or at least placing a lien, on your Chinese home.
I think this answers your actual question. If you have any more, please feel free to ask them! If you would like me, feel free to ask for me in the title. Most, but not all, of the experts will respect your request. If you have found my answer to be helpful, please rate me highly! I would really appreciate that!
Again, thanks! Have a great week!