[Jason.]

The definition of the word "bullying" is as followed,

Bullying: Using power or superiority to threaten, dominate, abuse or intimidate somebody considered weaker than ones self. Bullying behavior is often repeated and has the potential to be repeated over time.

Bullying involves action such as: making threats, spreading rumors, attacking someone physically or verbally, and excluding someone from a group on purpose.

Rationalizations for such behavior sometimes include differences of social class, race, religion, gender, sexual orientation, appearance, behavior, body language, personality, reputation, lineage, strength, size or ability.

Judging by the definition above, the BIB is what is similar to what is happening to Alicia.

Katie, and Cami. Both of which are powerful dominant characters.
Alicia, considered weakest of the pact.
It's been repeated with Katie calling Alicia "thick" on multiple occasions, which links to the BIB about ability. Cami calling Alicia a "bitch" more than once, repeated. Cami also bitching about Alicia's appearance. Again this links with the BIB, about appearance.
Both of the examples, I have given above, are what seems to be attacking somebody verbally. This is therefore, bullying behavior.

I think I've made my point.

Source: Own knowledge, bullying.org, Wikipedia.