Will my wife's credit be affected if I file for bankruptcy

If you have separate credit than your filing should not affect your wife's credit in anyway.  In fact, if you have no joint accounts or joint assets, then your bankruptcy will not affect your wife at all.  However, unless you are living apart and are legally separated, in a situation where only one spouse files, the income and expenses of the non-filing spouse is required so that the court, the trustee and creditors can evaluate the household's income.  This, however, in no way obligates your wife, either legally or financially.  Obviously, to the extent you have joint accounts, she will be affected.  The same holds true for any joint assets not exempted by law.