You would do well to check the BLS-2016 manual. In fact, I will refer you directly to that, because the instructions I would reply with here would be so long, you'd do better to see it as CDE presents it (I would be re-inventing the wheel, so to speak).
In the Help menu, the item “Program Manual” is near the top, and it will display the full manual in .PDF, opened in Acrobat Reader (this is one reason why Reader is a system requirement for BLS). In the manual, find chapter 16, but skip to page 181 and following, as this chapter spends 10 pages describing standings sheet options before getting into customized reports on the above page number.
You really don’t have any way of centering per se, but indenting does exist.
The question “What’s a Style?” is addressed on page 182. Read through what the manual says about styles...once you are in the "Modifying a Style" area as shown on page 184, you will be able to scroll through the many elements that can be part of a Style. Scroll all the way down, as the final section of that enormous list is “Spacing & Formatting”. As mentioned, you can't center, but you can insert a space, or indent 1/2", 1", 2" and 4". You will have to experiment to get this as close to centered as possible.
Exploring this area could open other report options you may have not previously considered.
Do understand that you could modify a style to make it 2-column (or more) which could extend it to the width of the page, if that would be a palatable solution. Also remember that if your Style includes an element, say a team or bowler name, and later a very long name goes therein, it will throw off how centered the report winds up being.
For future posts, please include a version number of BLS-2016. The format is 28.0#.##, which is visible in yellow on the opening screen, or in the main window’s title bar once a league is open. This helps in case there's a software issue/bug that may have cropped up during the course of the season, to make sure that you’ve done all updating, etc.
Always check, download, and install the most recent update of your software to ensure that issues may have been corrected.