score:2
Either is technically possible, I think, but only one makes sense in the context. Here eva in āḷārasseva means "only", not "even", since we know that āḷāra indeed has faith, etc., according to the passage prior to this:
tassa mayhaṃ, bhikkhave, etadahosi — ‘na kho āḷāro kālāmo imaṃ dhammaṃ kevalaṃ saddhāmattakena sayaṃ abhiññā sacchikatvā upasampajja viharāmīti pavedeti; addhā āḷāro kālāmo imaṃ dhammaṃ jānaṃ passaṃ viharatī’ti.
"At that, monks, it came to me thus: 'not indeed by faith alone does āḷāra kālāma declare this dhamma in its entirety thus: "having known for myself with higher knowledge I dwell having attained it". Indeed, āḷāra kālāma dwells having known and seen this dhamma."
So the context implies that indeed he does have the faith, etc., he's just not alone in having that faith, etc..
Also, if it was going to be "but I have faith...", we would expect mayhaṃ pana rather than mayhaṃpi (mayhaṃpatthi = mayhaṃ+pi+atthi), since pi generally means "and, also", and not usually "but".