If you want to set display options for individual grade items that are different from the overall settings, you can adjust individual grade display options. From the Edit Item page, select to Override display options for this item and then choose the settings you want.
Note: Bonus grade items do not display to students with the grade scheme information like other grade items, no matter what display options you set. Bonus grades are calculated differently than other grade items and are only added to final grades after all other calculations. Therefore, students can only view the numeric points, and potentially the weight achieved, for a bonus grade, but no other grade scheme information.