My 11 year old stepson is the family boss?

I got married 3 years ago and have an 11 year old stepson. He has never been disciplined. None! My wife is afraid it will make him depressed and mad at her. You can imagine what a problem this can be for me. He is good at throwing a fit to get what he wants. He has no respect for his mother or me. My wife will not allow me to use "Time out" or some time alone in his room when he's a problem. He always gets his way. My wife does not respect what I feel is important in child rearing. I showed my wife two episodes of "SUPER NANNY." Nanny was good at getting control of a bad situation with spoiled brats. But she can't bring herself to dicipline her boy. She just spoils him more each day. What can I do to solve this big headache? Or at least make it a little better. Thanks a million for any help you can give me. .