Sentence number 1 focuses on an ongoing situation in the past, whereas number 2 focuses on a situation starting at some moment in the past that may or may not continue up to the present state of affairs.
May I also draw your attention to the following:
‘Who has been bullied’ is the present perfect passive. It can also serve as a passive form of the present perfect continuous, because, ‘Who has been being bullied’ while linguistically and theoretically correct, is overly complicated. No speaker of English - native or non-native - is likely to use it in conversation or writing.
It feels like dismissing grammatical precision makes more sense than prioritizing consistency. Both are equally important. In my opinion, your addtional information is often beside the point.
I think you could also say: If I were the parent of a bullied kid, I would talk to … (Here the question of confusion of the tense does not arise. It states the fact of having been bullied though not ‘being bullied’).