Many would have us think that there are two but there is only one.
For some strange reason or another there is this thinking that God will return to the natural Jew and yet God did when Christ arrived on the scene. When Pentecost came, literally, THOUSANDS of Jews were saved. Only a remnant, though Israel be as the sand of the sea enumerable, only a remnant would be saved, "such as should be saved".
The idea of the two brides arise because they are not convinced that Christ eliminated the distinction between a Jew and Gentile. God hath concluded ALL to be under sin, whether they be Jew or Greek, it didn't matter anymore. Circumcision of the flesh became circumcision of the heart. The race called "Jew" has no significance to God, "All have sinned". The beloved of God are those who are walking in Spirit and Truth. A true Jew is one who is circumcised in heart, and that can be both Gentile and Jew combined. In Christ there is no distinction.
But God has not forgotten those that He had foreknown, nay. The door is still opened for the Jewish people, it's still is to the "Jew first" if they want to give ear to the Spirit of Jesus Christ and claim Him as their Messiah.
Sadly, many are caught up with the false teaching that God has more favour upon the Jews than the Church, thus making a distinction, thus creating that God has two purposes and two brides. This is error. God has one Church. God lives in His body the believing saints, His Temple. He doesn't favour one nation over the other, He favours those that have His Spirit not a rebellious house that continuously rejects His Son even to this day.
1 Thessalonians 2:14 For ye, brethren, became followers of the churches of God which in Judaea are in Christ Jesus: for ye also have suffered like things of your own countrymen, even as they have of the Jews:
15 Who both killed the Lord Jesus, and their own prophets, and have persecuted us; and THEY PLEASE NOT GOD, and are contrary to all men: 16 Forbidding us to speak to the Gentiles that they might be saved, to fill up their sins alway: for the wrath is come upon THEM to the uttermost.
Now before anyone starts quoting Romans 11:26 PLEASE put together what Isaiah said in Romans 9:27. The "all" in 11:26 is the remnant of 9:27 which was going on in the first century. The Apostle was stating an existing fact, not prophesying about a yet future event.
If anyone teaches about the two bride scenario, this is where the cross starts to get watered down.