Alkaline water is a scam, IMO, as given fairly pure water, it doesn't take much of anything to get it alkaline, but with no buffering capacity, it won't push your body very far in the alkaline direction either...a little carb soda if you want to do it yourself.
Some of the techniques using hydrolysis may be fairly dangerous too.
The alkaline concept is sound, as it applies to diet. e.g. orange juice is acidifying, an orange, with the flesh is alkalising. There are some good articles in proper science magazines on the subject...alas the scammers have marketed the water.