Problem: When using “Text → Indent Selection” (⌥⌘[) I do not get the desired result.
Solution: Indentation rules can be configured. The system however has limits and perfect indentation might not be achievable.
Generally undesired indentation is not considered a bug, since the fix is often not possible, or require a lot of testing, tweaking, and knowledge of the language for which the indentation rules are created, and we (macromates) simply do not have the resources to spend on this.
Though if you do improve upon included indentation patterns, be sure to send them to the bundle maintainer.