To the right of this forum, there is a list of Top Questions About Cozumel, you can look there about the transportation to the hotel.
WIFI is in all areas at El Coz...around the pool, in the restaurants, lobby, and on balcony of the rooms. Sometimes I could get it in the room at the little table by the balcony.
They do have beach volleyball and also in the pool.
Yes, they do have wine.
They do have complimentary snorkeling gear, but I would highly recommend taking your own. You may also want to go to some of the other snorkeliing areas on the island and you will need your own. You'll need a good mask that fits your face and the hotel's may not fit you very well. They also have a limited time on using the gear.