How can a wrong date on the marriage certificate affect me in bringing my wife to the US?

Without knowing significantly more information, it is impossible to provide a legal analysis of complications relating to your marriage certificate and to the most appropriate steps to take to address that. What is the reason for the discrepancy? Is there any legal issue about whether the marriage was performed in a lawfully valid way? Etc. It would be wise for you and your wife to consult with an immigration attorney who, after learning all of the relevant information, could advise about eligibilities, options, and strategies to attain your goals, and who then could offer legal representation in the often complex application process.