The water will last indefinitely, but its plastic container taints the water. Plastic is made from petroleum. Over time, this will leach into the water.
I know what I'm talking about. I live in the remote Utah desert and regularly carry water in my vehicle, in 2-1/2 gallon jugs or 500 ml bottles. I change it at least once a year, because of the plastic taste pervading the water.
It would be okay to use in the radiator, and sprinkle on the lawn, but I would avoid introducing petroleum byproducts into my body. Research shows that petroleum is carcinogenic. Used motor oil is one of the worst.
In a stainless steel container, water would last a long, long time. In plastic, not so much. Even the best bottled water has a few microbes in it, that will eventually proliferate. Water poured from bottled water into larger containers should probably be sterilized a bit more by adding a few drops of chlorine bleach per gallon. This will stifle microbe production, at least longer than if you just pour and seal.
I buy bottled water for home, and rotate it. Rotation is key to maintaining fresh stock.
And no, you need not rotate rum, whiskey, gin and other spirits -- but you should play it safe and sample them on the rocks or with mixer at least once a month, if not more often.
In a SHTF situation, booze is very useful: fire starter, anesthetic, calmative, something of a sterilizer depending on proof, excellent sore throat medicine and a psychological booster (but a depressant if too much is used).
Rum and whiskey are perhaps the best emergency spirits, solely because their flavor is more tolerable than gin or brandy to non-drinkers.