In my humble opinion.. Yes. I feel bottle sacrifices just a little too much for the sake of being a single file distribution. The lack of any (mainstream) templating engine might hinder newcomers, and Flask uses one of the best python templating engines around. I also find Flask's documentation to be more extensive and better laid out. Overall I would recommend Flask if you want to write a full featured website, Bottle if you are looking to write some kind of API layer, or similarly bear bones functionality, and will not require many "batteries included".
