Some bonuses are based on individual performance while others are basically a profit sharing vehicle. Was there a document you signed early last year that gives the parameters and potential payouts? When it has been profit sharing based I’ve usually had to sign something that tells me what the company’s EBITDA targets are and how the bonus would payout based on those. If it is based entirely on a manager’s discretion then whether she likes questions or not you deserve to be given the chance to have your slight explained so you know what has to change. It is pretty stupid that you don’t know exactly why you weren’t given a bonus… and with only that information I don’t think you have a very good manager.

Unlike many others have stated above I don’t have an issue with you asking “why” on so many projects. Perhaps you can reframe the questioning in the future as trying to understand how this project and your work fits into the organization’s overall strategies and goals. But it sounds like your manager has a habit of reacting to projects rather than being proactive and knowing what is coming… so you and your colleagues get to adjust and react with her. Another bit of evidence that she may not be the best manager.

Good luck and hopefully it works out for you.