Is it OK to hit the bar right after going to the gym for drinks?

If you're hitting the bar immediately after going to the gym, I don't recommend it. After you exercise, you must replace lost carbohydrate and protein before you subject your body to the effects of alcohol. The exact amount needed depends on your gender, age, weight, activity level, etc, so consult a good nutritionist. If you recover adequately it should be fine to drink in moderation.