In Yosef's second dream [Bereshit 37:9-10] the sun,moon and 11 stars bowed down to him. The sun refers to Yaakov, the moon - Bilhah (or Rachel - Gemara Berachot 55a/b) and 11 stars - his 11 brothers.
So according to the Gemara, the moon part didn't come true. (Hence the Gemara learns that there is no dream without meaningless components) but seemingly the rest DID, so both Yaakov and 11 brothers bowed to Yosef.
and according to the Midrash (Bereshit Rabbah 84:11) It looks like the whole dream came true with the moon being Bilhah.
So both the Gemara and the Midrash hold that Yaakov bowed down to Yosef.
When did this occur?
Is it Bereshit 47:31 - which describes Yaakov bowing to Yosef?
I'm not sure though because:
1) According to Rashi's second explanation (on Bereshit 47:31) Yaakov actually bowed to Hashem - not to Yosef
2) Although in the dream it just says that the sun,moon and stars bowed to Yosef, from Yaakov's interpretation of the dream (Genesis 37:10) it seems that bowing means " to the ground" - which is not what Genesis 47:31 describes.