I had the Grout Doctor re-grout and re-caulk the bathtub and surrounding tiles. He told me to wait 24 hours before using the bathtub/shower. He did the work on Friday. Today is Monday and the caulk still feels tacky. I do not know if that is how it should be or should it harden? If so, how much longer should I wait?

Not sure which caulk he used but after 3 days it should be dry. I'd call him back, sometimes caulk that has been frozen will act like this.