A "feels like" temperature as it relates to the water warming in a bottle means nothing. The only thing that matters to your water bottle temperature is they actual air temperature. Humidity isn't a factor. Or if anything at all a very small effect on heat transfer as humid air is denser. Humidity and "feels like" values are meaningful to humans because we sweat.

So, no question the higher the "feels like" temperature the more you'll sweat, the more you'd benefit from cooler water, but it has no effect on the temperature of the water in the bottle. So, at least in the context of an insulated water bottle and how well it keeps water cool, you should be using the real air temperature, not a "feels like" temperature.