Any time a child has had a long period of successfully staying dry and then starting to wet again, it is worth looking into a little farther. Many five-year-olds (especially boys) will wet the bed, but the fact that he did not for an entire year and that he wets during the day is a little concerning.
It's great that you had him checked for a urinary tract infection (always the first step!). Since he is not improving on his own or with any of the methods you employed, it may be time to seek the advice of a pediatric urologist. They may be able to do a more in-depth exam and shed more light on the subject. Good luck!