Is Treatment For Bipolar Disorder Advisable?

Hi, I think my boyfriend friend has a bipolar disorder, his mother has it and he has the same traits as her, a lot of these cause tension in our relationship, he jumps from expensive hobby to the next and nothing is finished and all these half projects are worth my rent money, He has a lot of grand plans that are so far from practical. i.e. We are looking for a rental property but he won t consider looking at anything that doesn t have a double garage or a 5 car spot carport reglardless if we cannot afford it. He either is wholeheartedly with you or cold and distant but at the same time very paranoid about my feelings and what I m up to. When we re good we re really good but when we re not I feel like I m up against a brick wall. I m here to stay with him somfor our sanity I need to know, Is this something that we should get him help for? Or is this something I m just projecting on to him?