Since You said its BL, I think cover 2 is better because it looks more intimate(not as in overly intimate, I mean it as more familiar and trusting with each other) than the first, the first cover looks like they're not close and distant to each other -- it gives the impression that they're more like buddies rather than a couple.
Question Regarding cover 2: is the werewolf mostly in human form or in wolf form throughout the story? -- since you said its BL, if most of the scenes, the werewolf is in human form, I think it's better to incorporate it to the cover itself to give the readers an idea what the werewolf character looks like in human form since the human form appears more frequently in the story. BUT if throughout the story, the werewolf appears more frequently in wolf form, then keep the cover to your original idea to put a happy wolf in cover since it will appear more frequent in the story.
