Yes. There is one baptism (for simplicity, let us not hold in view invalid non-trinitarian baptisms that are quite rare). A baptism is valid whenever water is used, there is a willing parent and/or sponsor, nd it is done in the name of the Father, Son, and the Holy Spirit by one intending to initiate the baptized as a Christian. It can even be done, in emergency, by a non-Christian! For example, a Muslim doctor will validly baptize a baby on the verge of dying.
Therefore the vast majority of the baptized Christians are Catholic with the capital C. In fact, we do not make the distinction between Catholic and catholic, because certainly St. Athanasius did not have the distinction in mind when he wrote the Creed.
The next question is, what that newfangled Catholic does with himself. With Catholic sponsors he will hopefully continue a life of a practicing Catholic of Roman or some other rite. With Orthodox sponsors he will likewise will lead a life of an Orthodox Christian and, despite the fact that in obedience to his bishop he would not identify himself with the Church of Rome, he in practice will remain Catholic Christian, and we praise him for that (our dispute with the Orthodox is entirely with the bishops who resist union). If, however, he is raised in a Protestant background, he will separate from the Church not only nominally but also materially: he will not go to confession, or take the Eucharist. At this point he is a separated Christian.
This is as pertains the Catholic ecclesiology, not soteriology. All these people, along with the unbaptized, will be judged according to their works. A pious charitable God fearing Muslim may very well be saved by sovereign will of Christ; a heartless self-centered Catholic who punched every ticket in his church without a conversion of the heart may very well be lost.