1998 SSEI wheels will fit a 1990 bonneville right? Is the spacing any different?

Also, does anyone have an opinion of how the 9 spoke (3 groups of 3 spokes) wheels would look on a red (maroon) 90 bonneville? I think they would look nice painted a little darker color, like gunmetal grey. I need to find out how to do the photoshop thing

On GM wheels the offset is usually cast into the wheel on the backside. For instance our 90 has 16x7x46 cast into the wheel near the hub - offset is 46 mm.

yes the wheels will fit on. there were wheels that were used on the 91 bonnies and then used on the early production 92'*