I’m not very experienced with Illustrator-Scripting and it often seemed to me to be poorly implemented when compared to Indesign and Photoshop – which I suppose could also mean that I just do not have enough insight.
But as I have not been able to find such an option as you inquire about I seem confirmed in my opinion once more.
The only instances of »bleed« I found in the Object Model Viewer are pdf- and print-related.