Yes. There is nothing in the California Civil Code or the California Penal Code which prevents your landlord from asking your aunt to pay the rent that you haven't paid, especially since your aunt was previously a co-tenant or guarantor.
Frank W. Chen is licensed to practice law in the State of California. The information presented here is general in nature and is not intended, nor should be construed, as legal advice. This posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, consult your own attorney.
You may be lucky that the landlord was generous enough to allow your aunt to pay the rent. From what you have written it sounds like the landlord may have been entitled to evict you and request damages for the back rent. It sounds like you and your aunt would have been liable for the back rent. Even though it may seem like what your landlord did was wrong, from a legal perspective it seems like he was trying to be helpful and understanding to your situation.
The information contained herein is general information only; is not legal advice; and should not be relied upon. If you have a pending legal matter you are advised to contact an Attorney in your particular jurisdiction for representation. The above information does not create any attorney client relationship with Phillip B. Rose or PBR LEGAL.