'boyfriend material' is correct and usable in written English.
It is used to describe someone who has the qualities that would make them a good romantic partner. For example, "I think he'd make a great boyfriend because he's definitely boyfriend material."
"He's perfect boyfriend material," another whispered.
All of that probably makes him excellent boyfriend material.
He was sweet, even if she did not yet see him as boyfriend material.
"He definitely stayed on my radar screen, but he didn't seem like boyfriend material," she said.
Up to that point, she did not think of him as boyfriend material, much less a potential husband, because her parents wanted her to marry a Korean.
With his mad red hair, thin lips and wrong kind of Doc Martens, James is not her idea of boyfriend material, but the two quickly become inseparable – best friends of the fiercest kind.
Even I can see Deyes is perfect first-boyfriend material.
In other words, they are perfect best-friend or cyber-boyfriend material.
And while she's a maestra of invention, Gerstler is not above recycling language when it's the right thing to do, as it is in "Untranslatable," where she strings together every cliché in the book ("He picked me up at a greasy spoon," "he starts giving me the third degree") to describe a real piece of bad-boyfriend material who's as irresistible as an ice cream cone on a July afternoon.
You know: two friends who like each other but not as boyfriend-girlfriend material so they have no problem sleeping together in between "real" relationships without things getting weird.
He's not your boyfriend or long-term material -- he's someone who you have a good time with, a man who provides you with the financial benefits that make your life easier and more fun.
