your s-corp PTET should be a deduction on the s-corp return (federal portion and an add back for the IL S-Corp income tax)- the whole purpose behind PTET is so the state taxes on partnerships/s-corps income are deducted by the entity to avoid schedule A entry on the owner's 1040 since the deduction for taxes is capped at $10k. (it's not deductible by you since it was paid by the S-corp). as a matter of fact, the amount should appear on line 33 of your Illinois K-1 because it's not a deduction for personal state income tax purposes.
