I am sure there's a reason why you are on Methylphenidate and not on Bupropion.  Just because you've heard from other people about Bupropion doesn't mean it'll be good for your condition.  Psychiatric medicines unfortunately are not like cough and cold medicine.  Every patient is different,  diagnoses are different and hence meds differ.  Please ask your treating psychiatrist to explain to you the difference, I am sure he/she will tell you why you are not on Bupropion and what he meant by Methylphenidate and Bupropion being similar medicines.

They both are different but depending upon your complaints, it may not be helpful to take both together. Bupropion, though antidepressant, also helps with anxiety, smoking cessation and a few other conditions. Methylphenidate on the other hand is mainly used to help improve concentration in cases with ADHD. So until and unless the history is there, it is difficult to answer why your doctor said you what he did.

Who told u that they are same?