While the relationship between Elisa and the tinker is hardly confrontational, he's definitely an antagonist in the story. When he enters the action, he immediately shakes up Elisa's world. And at the end of the story, he wields an immense amount of power over her by destroying the chrysanthemums she worked so painstakingly to cultivate. The jerk.
But maybe we should cut him some slack. After all, it's entirely possible that the tinker, like Henry, has no idea what's going on in Elisa's head. It's therefore equally possible that he trashed the flowers because he was being practical. The pot, he can use. The flowers are just decoration.
Henry is a less obvious choice for the role of antagonist, but the shoe fits nonetheless. Henry, though hapless, bumbling, and well-intentioned, represents the social strictures that keep Elisa contained. He's the husband, the provider, and presumably expects Elisa to keep house and garden without complaint. When he suggests she try out her "planters hands" on the orchard (12), he dismisses her positive response out of hand. He seems confused by Elisa's strength, just as society doesn't quite know what to do with a strong woman. He wants to please her, but he can't conceive of her as anything more than a housewife, and therefore plays a role in her isolation.