A guy who checks in with his mother once or twice a week is clearly a keeper. He respects the woman who gave him life, but he isn't so attached that he requires her opinion to select a movie at the local Redbox.
If you suspect that your man and his mother have an unhealthy phone relationship, consider keeping an informal "Mommy Phone Log" to track their convos. Five minutes every morning is one thing, but an hour or two every evening is a totally different story, especially if it regularly cuts in one your one-on-one time. Once you have a better idea of how often they talk to each other, consider any extenuating circumstances. Is she going through a rough time, like a family crisis, illness or the loss of her husband? If so, back off on your quest for independence until things settle down; she probably needs her son's support more than ever right now.
If everything's hunky-dory, though, it's probably time to politely suggest that he taper back on his phone time. Try not to sound jealous or resentful when you make the request. Simply let him know that you both work hard all day, so you look forward spending your free time building a marriage and life with him, not listening to him re-hash last night's episode of "Survivor" with his mother.