Yes, all string values are translatable through the supplied POT/PO/MO files. Currently this plugin has been translated to English, Spanish and Dutch.
Using qTranslate X, the coupon message for Auto Coupons can be translated using shorthand tags, e.g.
[:en]This is English[:es]Esto es Español[:].
In WPML translatable items appear in the context woocommerce-jos-autocoupon in “String Translations”.
Translation has been tested with WPML and qTranslate-X. Under certain circumstances WPML has caused some side effects.