Tuition waivers for an employee's spouse is generally treated as a taxable benefit, so the additional withholding taken from your paycheck was correct. The university is required to withhold federal and state income tax as well as FICA taxes.
You can verify that the amount added to your taxable income matches the actual value of the tuition waiver to ensure that the correct amount of tax was withheld. However, if the withholding was correct based on the value of the tuition waived, you won't be able to recover that amount from the IRS as the waiver was correctly reported as taxable compensation.
