To the best of my knowledge, once you receive delegated sp, whatever reward you get from Curation is shared between you and the steemit account you upvoted. You get 0-24% if you upvote the post or commit within 30 minutes of its being posted and 25% if you curate 30 minutes later. The account upvoted gets 75% of the reward.

I have received delegated sp on a few occasions from @neoxian and on each time, I shared the reward with the accounts I upvoted.