Yes they are. Even thought Neodymium magnets are the strongest permanent magnets in the world, they are safe around both cards, and phones.
The manufacturer does not recommend using the magnets near a pace-maker.
Hotel swipe cards are designed to be rewritable and proximity to any electronics will wipe them out: magnets included. It's just plastic so if it gets wet in a regular pocket nothing will happen.
Please check the manufacturer for details.
We are using the Gooper magnetic technology used in the worlds most waterproof dry bags. We have worked together with Gooper to develop a waterproof pocket suitable for clothing, which not only closes itself but is ergonomically shaped , comfortable and convenient to use. https://gooperhermetic.com/about/