The difference is the degree. The AVMA policy on terminology states that a veterinary technologist is someone with a bachelors degree in veterinary technology. However, only one state in the US legally recognizes the title "veterinary technologist" and in all the rest the credential granted with always be licenesed/registered/certified "veterinary technician" regardless of whether the person has an associates degree or a bachelors degree.
You can make more money with a bachelors degree if you choose the right type of career--research, teaching, working for drug companies, working in specialty practice, etc. But it's as common that you will make the same money as any other veterinary technician right off the bat.