There are several issues to be thought:

• Does any translation api exist the bot can be use?
• The version history must be copied to the translation target due to license rights
• transferbot.py is able to copy any page from source wiki to destination wiki including the version history which is saved to a defined subage but it cannot translate yet. Anyway this script can be reused for translations too if there is a translation api
• A better way than copying the version history would be a version import. But this needs cross-wiki import rights. As long as wikimedia site farm has this ability for cross-wiki imports the plain import like it is done by transferbot.py should not be made
• A machine translation is not a good idea for an enzyklopedia; it needs human redacting. Therefore bot should import and translate from a wiki to a draft target only

Also look into https://www.mediawiki.org/wiki/Manual:Pywikibot/Create_your_own_script