If bottled water will help you sleep at night I see no reason not to use it.
Funny. I use Reptisafe for my snake, but not my spiders. I don't think it ever even occurred to me to use it with my spiders water. I'm sure it had something to do with adding electrolytes to the water or stimulating slime coats or some such. I'm sure either way is fine. It's not like they aren't going to put substrate in their bowls anyways. Even if they don't fill them, they give them a sprinkle.I'm a bit too impatient to let tap water sit overnight. I've been using Zoo-Med Reptisafe dechlorinater for years without problems.
If the water has been purified through distillation, that might lead to other problems. https://en.m.wikipedia.org/wiki/Distilled_water#Health_effects