"become affiliated" is a correct and usable phrase in written English.
It means to become officially connected or associated with a certain group, organization, or cause. Example: After years of hard work and dedication, he was finally able to become affiliated with the prestigious law firm.
Reuveni Pridan is negotiating with the Interpublic Group of Companies to become affiliated with an Interpublic agency.
It had become affiliated with manufactured culture, with the crowd, and with the sentimentality and repetitive stylization that crowds, in their quest for a common identity, often crave.
If we can also become affiliated with some of those people, we can bring a new level of excitement to the property".
Some Republicans may have become affiliated with the Tea Party movement in the hope of aligning themselves with an invigorated and energetic grassroots conservative movement.
By then Mr. Kurtti had become affiliated with Allied Productions, a nonprofit founded by ABC No Rio's directors, Peter Cramer and Jack Waters, along with Carl George, who organized the Participant Inc. show.
Flemmi had recently become affiliated with another up-and-coming gangster, a cunning and disciplined South Boston hood named James Bulger, who was known, owing to his platinum hair, as Whitey.
The new station was set to become a Network Ten affiliate, however WIN's links with the Nine Network caused the Nine affiliation to move from QTV, which itself became affiliated to Ten.
Accordingly, the elementary affiliated kindergartens had to transform themselves into self-sufficient pre-schools, and became "affiliated independent kindergartens".
The Institute for Social Research thus became affiliated with Columbia University until 1949, when it returned to Frankfurt.
Gabon founded a football federation in 1962, and it became affiliated with the International Federation of Association Football the following year.
What I had been dreading ever since the magazine became affiliated with RGS had finally happened.
