Yes, if you have not submitted IL-W-5-NR to your employer then you would file a resident Iowa return and a non-resident Illinois return.
A reciprocal agreement, also called reciprocity, is an agreement between two states that allows residents of one state to request exemption from tax withholding in the other (reciprocal) state. This can save you the trouble of having to file multiple state returns.
Read below for more information on your state's reciprocal agreement?
https://ttlc.intuit.com/replies/3299954
https://ttlc.intuit.com/replies/4776822