I agree that "co-dependent" has a negative connotation as it has become a term of art in the substance abuse context. I'd go with "symbiotic" or "synergistic" for a positive connotation or "mutualism" or what Prism said for a more neutral effect.
I think 'co-dependent' has quite negative connotations; it's often used to describe toxic relationships where one person has a substance abuse problem and their partner is an enabler. Having reread your OP, you'd be better off with 'symbiotic'. If the relationship is very beneficial for you both then I think 'synergistic' would be appropriate.
Thanks that's just what I needed. I think that symbiotic is more nature but co-dependent sounds more appropriate to describe a business relationship. Thank again - you'll make me look really smart!! Have a good weekend
...something that lives off something else but that something else needs the original something to exist. The case is where I am a tenant and I am my landlord's main source of income. If they evict me, I couldn't find anywhere else for the same price so couldn't run my business but if I could leave (lottery win, or offer of free rent) then they would probably go under...sorry not much to go on. Think its usually applied to nature rather than commerce!