Information is quoted from developers on FO:NV forum, topic "Nuka Cola Quantum". http://forums.bethsoft.com/index.php?/topic/1107982-nuka-cola-quantum/
Gstaff: "I was just playing the build you guys will be able to play at QuakeCon and stumbled across vending machines for Sunset Sarsaparilla and Nuka Cola. I'm not sure about other Colas (I hadn't been paying too much attention to that). I'll see if there's anyone that can clarify what else is out there."
Gstaff: "Yeah, the other currencies include Legion Money, NCR's money, and cap. Of course, you also have chips at the casinos."
J.E Sawyer: "As Gstaff wrote, both Nuka-Cola and Sunset Sarsaparilla are available as the common soft drinks. In Hardcore Mode, both negatively affect your dehydration (H2O) meter but Nuka-Cola can help stave off sleep deprivation (SLP) a bit.
Nuka-Cola Quantum was limited to the D.C. area, so the "common" unusual variants of Nuka-Cola in the Mojave Wasteland are Nuka-Cola Quartz and Nuka-Cola Victory (please see your local Nuka-Cola representative for nutritional information).
Nuka-Cola and Sunset Sarsaparilla both contribute bottle caps to your cap total, though some specially marked bottles of Sunset Sarsaparilla have... "special" caps."