No, i'm refering to : https://dev.twitter.com/rest/reference/get/statuses/lookup
And the relation between tweets and promoted tweets is not 1 to 1.
Imagine you have 1 Tweet:
Tweet1 -> ID = abc
And you have 2 Line Items and you want to promote that tweet in those 2 line items, so you'll get:
Promoted_Tweet 1: ID = XXX, tweet_id = abc, line_item_id = qqq
Promoted_Tweet 2: ID = YYY, tweet_id = abc, line_item_id = www
Is the same if you uses the same tweet to promote it in a different campaign.