You can also edit grade visibility options for individual grade items via the Edit Item page by setting Display Options.
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 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.