Does the 1998 Pontiac Bonneville have an idle control valve?

Yes, the 1998 Pontiac Mid-size Bonneville with the 3.8L V6 engine does have an idle control valve. The OEM part # is 17112929. Aftermarket brands will cost around $40-60. It's a small part, usually located on the throttle body. Two bolts to mount, and it's got a 4-pin electrical connector.