I have taken Metoprolol Tartrate for many years and I'm currently on 75mg per day. I have an occasional weekend beer or a glass of wine and experience no side effects. YOUR MILEAGE MAY VARY, but I wanted to give you my experience with Metoprolol.
Actually, the question is best answered by your doctor. It would depend on any other medications in addition to Metopropol, health conditions, and how much alcohol you'd be drinking. You might also ask your pharmacist.
The following site offered this caution, in part. You can visit the site for the complete answer on food and alcohol, but your doctor would be the best reference.
http://www.drugs.com/drug_interactions.html
"Metoprolol and ethanol may have additive effects in lowering your blood pressure. You may experience headache, dizziness, lightheadedness, fainting, and/or changes in pulse or heart rate. These side effects are most likely to be seen at the beginning of treatment, following a dose increase, or when treatment is restarted after an interruption......"