No. You didn't move up a bracket, but more of your income was taxed at the 25% rate. The entire $3,000 would have been taxed at 25%. So, that would result in $750 extra tax. Also, the bump in income may have affected other deductions and credits. I would suggest increasing your withholding. Please view the Turbo Tax FAQ below for more information about the 2016 tax brackets.
https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/2013-Federal-Tax-Rate-Schedules/INF120...
