if it was reported on your Fed return at 1099-INT Box 3, that should be flowing thru to your state return as a subtraction from Federal income. Not sure what line that is on your NJ return but hopefully that points you in the right direction.
This line is usually a total of all subtractions from 1099-INT Box 3, 1099-DIV US Gov Obligations, 1099-OID etc but there is no drill down so if you have other Treasuries besides the savings bonds you'll need to understand the total subtraction expected and review your 1099s if it doesn't jive.
Note - if you have any accrued interest adjustment on the 1099-INT and more than one of Box 1/3/8 has income then this can cause issues as there is no way to tell TT which box the adjustment applies to and you need to split the 1099-INT.
