Well, he wasn't very expressive about his mother, but the conditions in which he grew up didn't allow him to show emotion for anyone. Besides, his father was given a more important role in his life, since he spent his childhood and youth in prison because he was paying his father' sins.
His quest to find him took lot of years, and when he succeded he was pretty dissapointed because of how his father turned out to be. But I think his mother did have importance for him, only in a deeper level, and that King showed us clearer.
In Gail Simone's amazing Secret Six run just before Flashpoint, we watched Bane's hell, that was basically her mother's dissapointment at watching how Bane never overcame the prison and his fear of loneliness.
Usually, we see the importance of the paternal figures in both, Batman's and Bane's cases, so it was cool that King gave importance to both of their mothers, probably influenced for King's lack of a father figure and being raised by his mother and grandmother