Maybe if they continued over a period of time to be openly bitchy, goady and heckle it might constitute bullying behaviour but what we saw on TV last night did not constitute bullying in my opinion.
There were only two of them actively bitching, the others were mostly silent, which I took as meaning that they really weren't that bothered. Danny & Arabella both held their own and were neither coerced nor vulnerable and others took their side.
Two people acting in a childish way does not constitute bullying. If they behaved that way at work, you wouldn't be able to formulate a case for bullying. You might be able to give them an informal warning for unprofessional behaviour, but I doubt you'd be able to construct a case for a formal warning. It was a vocal disagreement and this shit happens.
The next day the air was cleared - whether under duress or otherwise and the disagreement is over now - in less than 18 hours.
I don't particularly warm to either Amber or Anna, but I really think suggesting that they bullied Danny and or Arabella in this instance is misunderstanding bullying. They were angry and pissed off and they vocalised that. I disagree with their point of view and how they said it and I think that neither of them behaved well or showed themselves in a good light - but none of that adds up to bullying.