I should think so, unless SetEnvIf has rules all its own. (I use the special form BrowserMatch but it's the same thing.) You can put in an override saying
Allow from all
so they have no excuse.
Interesting to know that the Imagebot pays its own separate visits to robots.txt. I thought the robots.txtbot did the work for everyone.
There is a special rule for the regular googlebot which may also apply to the imagebot. The moment the googlebot is mentioned by name in your robots.txt, it looks only at those lines that use its name. That means that if you have any google-specific rules but you also want it to follow the general rules, you need to say everything twice.