Buck and Tommy are good for each other...
...however the problem they face is that their trauma is the same but they have different trauma responses. Buck clings to people, versus Tommy who pushes people away. Because of that they're having some communication issues, but I think that will be really good for the writing to give them a slow burn and finally get together at the end. I'm planning on writing a tumblr post about this.
Tommy's comment on being competition with Eddie has nothing to do with a romantic tie, and everything to do with the comment that he made back last season about the 118 being a family.
He's never had that stability.
I think it really has to do with Tommy being super insecure about how Buck and Eddie's lives were so intertwined due to the 118, and so he's projecting a little. I don't think he realizes yet that Buck loves his friends in the same way he loves everyone—with everything.
I don't think Tommy has ever had any steady friends, and especially with the comment he made in the most recent episode about how Eddie just stopped talking to him once he and Buck broke up. He doesn't know what a healthy friendship looks like, which is why he doesn't realize that what Buck and Eddie have is a deep friendship. Tommy is someone who comes from a severe lack of affection of any kind except for what he probably found in his first queer relationships, and so he's seeing things through that perspective.
It's going to take the rest of the season for them to communicate and figure out where they're meeting, but I do believe that Buck and Tommy will be endgame.