I am allergic to septra (sulfamethoxazole and trimethoprim) sulfa antibiotic , would i be allergic to zinc sulfates as well that's in my vitamins?

No worries: The "sulfa" in antibiotics refers to the drugs called sulfonamides, such as suflamethoxazole, one of the drugs in Septra® or Bactrim®. The sulfur atom in these compounds is not the reason for allergy to them. To my knowledge, simple sulfur salts like sulfides, sulphates, etc don't trigger allergic reactions; and even if they did, I would not expect a cross reaction with sulfa drugs. No worries.

No: There is no cross sensitivity among sulfa, sulfate , and sulfite. Sulfates are usually very inert.