I'm not saying ignoring people is bullying! It's not, everyone should be free to get on with their work and not have to socialise at work, but I'm not sure what OP is describing could be classed as bullying (unless there's more to it), it's almost like she wants them to like her and make an effort with her, but doesn't put any effort into getting to know them either, but you can't really accuse them of bullying if all they're doing is ignoring her.
I was told to meet them halfway now they acknowledge my presence.
Join in more with pleasantries which has been impossible given they ostracized me for a year .
If she's socially awkward they may find it easier to ignore her, she's already made her mind up about them from the sounds of it, and doesn't think much of them at all, and the fact that the bosses have basically told them to work together to overcome it makes it seem like there's fault on both sides.
Like I said I know people like this, even in my family, there are some REALLY socially awkward ones and it can be a real effort to get to know them better, as they don't seem interested in knowing anything outside of themselves, so it can be difficult to get a conversation going, you have to be quite unselfish and patient and just be happy to talk about them and what they like, ask questions and constantly 'lead the witness' if you like, to get them to open up, they never ask me about anything I'm doing EVER, how my work, child, DH, pets, hobbies etc, literally NOTHING, it's like they don't seem interested unless we're talking about something that they are into. I love them so am happy to spend the time with them, and shoot the shit about their interests, but it can be quite draining as the ebb and flow of normal conversation just isn't there, I can totally understand how other people just can't be arsed with it and choose to see it as ignorance instead, some of my other family members have this view.
It's a shame because they are nice people, but they can't seem to get past this social anxiety, but instead of realising that they're the ones being aloof and 'ignorant' they seem to blame everyone else for not trying harder with them, and say things like 'why should I' (try to get to know them), then they moan that the same people won't talk to them, or ignore them.. I personally think it's a defence mechanism to stop them being 'hurt' by people, but pushing people away can be a lonely way to go through life.