Your spouse is able to deduct the IRA contribution because for her the MAGI $189,000 or less applies. For you, since you are covered by a retirement plan at work, the MAGI $101,000 or less applies a full deduction. With a MAGI $121,000 or more there is no deduction.
Please see
Please keep track of any nondeductible contributions to be able to track the basis you have in the traditional IRA.
