Is it normal to have bloating a month after gallbladder removal?

Not unheard of: It's not usual, but not unheard of, to have some persistent bloating. It is NOT due to a lack of bile, or persistent CO2 in the abdomen. Just maintain a good healthy diet, no restrictions, stay hydrated, and maintain normal activity. Perhaps add some yogurt to your diet. If it continues, I suggest you discuss with your surgeon, but it should resolve. Good luck.