There is a difference there.
It is referring to a marriage of 2 unbelievers. The wife becomes a believer while the husband remains an unbeliever. The wife is not given license to divorce her husband just because he is an unbeliever in that situation, but rather to pray for her unbelieving spouse, that God would save him.
I did not completely accurately apply the verse about being unequally yoked, however, I do think it does apply to a person who is a believer, meets an unbeliever. The passage is not saying that you should have absolutely nothing to do with unbelievers as a Christian. However, you must acknowledge that you believe in completely different things. For the one who rejects the truth of Jesus Christ, the believer cannot pretend to walk in agreement with them, for they have completely different perspectives on the truth of God.
Contextually, the passage is referring to the church being closely involved in relationships with unbelievers. As Solomon has demonstrated, when a believer is intimately involved with an unbeliever, it is not the unbeliever that is persuaded to the others view, but rather the believer is distracted away from the truth of God by the unbeliever.
I honestly believe that this does have application in romantic relationships. If a Christian is dating an Atheist, the Christian will be, not might be, will be distracted from the truth of God, and their walk with Christ will be challenged continually by being in a close relationship with one who rejects the truth of God.