Um you have your facts mixed up.

Obama originally tried to get around needing congressional approval by refusing to call the deal a "treaty." Congress saw through that and passed the INARA.

The senate then tried to pass a separate resolution that blocked the Iran deal, it FAILED.

Therefore, Obama's Iran deal was valid. Congress wasn't able to get enough votes to block it and that's the only thing they voted on.

The only thing they were able to pass is that every 90 days the president has to recertify the deal based on whether or not Iran is following through with their obligations and so far all evidence points to the fact that they have been.