Can my step dad boss me around?

i want all of your opinions...my mom remarried to her best friends x-husband (my moms best friend had a daughter i was best friends with) his name is rene. after that she quit her job, he joined the army, and we moved. rene and her have been together for about 8 years now (i can not stand him) hes SUPER headstrong and has a short fuse. i always tell my mom hes not my dad (and than always get grounded) and she tells me hes more of a dad than my biological dad was...but its not like my dad could always be there for me cuz my mom moved me away from him (i only see him twice a year: during part of summer and every other xmas break). rene coached my soccer teams at the Y a few times when i was little and my mom never lets me forget it...she says he done alot for me and has been a great dad to me and i have to listen to him and call him dad "or else" but hes gotten to the point where he yells at me for litterally everything and he grounds me without telling my mom anything and he takes my cell phone and goes through my texts, i've never liked him and my mom knows that...every holiday him and her get into a huge fight and she leaves me alone at the house with him and he scares the hell out of me so i spend most of my time locked in my bathroom waiting for the yelling and bbanging on the door to stop. its like he thinks he can do watever and that hes really my dad but hes not. my friends say that he cant boss me around like that and hes not my dad but i get yelled at if i say otherwise....should he be able to tell me wat to do, ground me, take my phone, go through my stuff, and tell my mom how to raise me than basically tell me im a bad kid (even for the smallest things i do?0) and should i be forced to call him my dad?