This will be a while longer, I'm not confident it will even be here by Christmas. The last KS update (August 3rd.) said this about the Compendium:
Devil Pig Games wrote:
The final french version earned 20 more pages with your help! Now, we will send it soon to the english translator, after we add the last remarks about it. The translation of a 104-pages document won't be fast, but the translator has already received the necessary docs to prepare the job.
After this translation, as for french backer, you will be able to read it and verify it in english. That may lead to new modifications in both french and english versions.