I agree about it being hodgepodge. Sometimes all I find are the pay bottles, and I'm unsure if I can take one of those, as I was told 2 bottles daily are free. I just don't know if it's those 2.
What I did discover is that in the hotels that actually give them to you, you have to either drink or hide them or you won't get 2 more
There should be a standard all hotels adhere to.