The short answer is: No. You can find titanium cups, pots and pans, and more, but no water bottles.
Chlorine Dioxide tablets
Chlorine Dioxide tabletsBut what I’m not clear about is: What exactly do you need it for? Not to brew up tea, I gather. It sort of sounds like you want to boil water for safety reasons, which I understand. But let me say two things about that. One, you could always pack some Chlorine Dioxide tablets ($10 for 50 tablets; one tablet per quarter of water). It’ll kill essentially anything bad in the water, including giardia, cryptosporidia, and viruses. It does have a down side: it’s slow, requiring four hours. Potable Aqua Iodine Tablets ($6.75) are faster (30 minutes) but don’t have quite the killing spectrum.
The other thing to consider is that if you really are in a survival situation, why worry about the water? You’ll be rescued—or not—before anything in the water gets you. And once you’re out, you can be treated for whatever it is you drank.
Anyway, while I am all for packing light, I don’t see anything in a small fanny pack that gives you the backup you need in an emergency. I still adhere to a basic list that includes extra food/clothing, matches, flashlight, first-aid kit, knife, etc. That doesn’t mean packing more than six or seven pounds, in most cases. But it does give you a cushion. And room for a small titanium pot.
Good luck!