Love them !!!!
How would you waterproof the labels so they last?
Waterproof the bottles? Myself, I will use spray adhesive to secure labels to bottles; allow to dry; then I will use clear packing tape and tape over the labels - making sure that all tape is of the same length so it will be neat. I've seen this suggested when people were making labels for water bottles for parties.
You could also use a matte spray sealer over top of the labels. Krylon makes some that you can get at any craft store. Mod Podge would probably work too!