Bella...You never got Clem's answer because your teammate splatted her. Clem probably would have accepted your apology; heck, probably even apologized herself and argue she deserved what happened, even if it was an accident, and it took meeting Whinter to make her let go of what ego she had left. So no, it wasn't a "fool's errand" to try and make peace with Clem. Though I will argue you really chose poorly when it can to where to give your apology. A battlefield is hardly the place to pick for such a discussion.
Jonquil and Marian, on the other hand, is still in the air. I'd expect both to have apologies for Bella if an amiable ending is where things are headed. Jon I can see being split, blaming Bella for hurting a childhood friend, and possibly ending a romantic relationship between them as well, but knowing Bella didn't mean for what happened to happen.
Marian, though, is more...complicated, and thus harder to predict. How bad was Bella's behavior leading up to the incident? Did the need to win blind Marian and cause her to believe winning was more valuable than a childhood friend? How much of Marian's decision was honestly hers and how much was Vadelma's? How much influence did Vadelma have, both on Marian and on Bella? Could Vadelma be more involved in the accident than we believe? Who could be a bigger obstacle between you and your romantic interest than their best friend? Who would think twice about your teammate and 'friend' handing you some gear?
Maybe the accident wasn't so 'accidental'...if you want to get paranoid about it. Because if you do, there's a list of questions to be asked.