I figured it was more of an SQL question than a Magento so I asked on the regular Stackoverflow as well, here's the answer
INSERT INTO review_store
SELECT review_id, '2' as Store_id
WHERE Store_id = '1'
I also had to apply the same logic to the
review_entity_summary table, which has 6 columns:
store_id. The first columns is PRIMARY so I had to skip it so it'll automatically create a new value. SQL query:
INSERT INTO `review_entity_summary`(`entity_pk_value`,`entity_type`,`reviews_count`,`rating_summary`,`store_id`)
WHERE `store_id` = '1'
Then in order to have the STARS displayed I had to go to
catalog > reviews and ratings > manage ratings, click on the rating and add the new store.
I hope this can help others with the same goal.