The promise of the potential of the possibility of a bonus which never comes to fruition. The false (faux), never-intended-to-be-given promise of the potential of the possibility of a monetary bonus whose conditions are never met and which never comes to fruition.
After working diligently for several months in anticipation of much needed monetary bonuses, John realized his fauxnus structure.
A bonus that was promised to you that never came to fruition.
Ted was promised a bonus at the end of the sales quarter, however it turned out to be a fauxnus when his boss told him he could not give it to him due to unforeseen cost cutting measures at the company.