Neurontin and antidepressants are commonly prescribed together, so there should be no problem with that. Prilosec, I believe, would not be considered an antacid in the way I think that is meant for this purpose, but should double check with your pharmacist.
http://www.drugs.com/xq/cfm/pageID_1150/int_0/qx/index.htm
Copy and paste it into you're browser and just put in all the meds you're currently taking and it'll answer your questions.