Pokemon adventures is often considered to be more canon to the games. Even though the manga was not made by Satoshi himself, you can see how canon it is to as Satoshi Taijiri once stated, "This is the comic that most resembles the world I was trying to convey." 

While the current producers of the Pokemon cartoon series have tried to make all the official movies to be canon to the cartoon series. As the series is only canon to things relating to Ash Ketchum.