Not the buttons, but the toolbar can be centered.
- Add the buttons to the toolbar.
- Set the toolbar's Align to alNone and AutoSize to true.
- Use the Anchor Editor to anchor the toolbar to the top of the form and to center it horizontally.
- Done.
Or, if you want to have a bar running across the entire screen width with centered buttons, put this toolbar into a top-aligned and auto-sized panel.