H1 B Amendment

Hi,I have H1B with employer A which is valid till sept 2016. I had my LCA filed for state B and it had address with city C mentioned in it. I used to work at a client location which is different from that address but its in same city. Both the addresses (the one on LCA and the client location i used to work) where in same city and state. But , both the address has different zip code though they are in same city.Now, recently i moved to a different project and stopped working in client location. My new project offered me to work from home and since last 4 months i am working from home which is in same city. Its zipcode is same as my client location address zipcode.My company sent me an email saying my H1B needs to be amended. But , i came to know that an amended H1B needs to be initiated only if there is a change in location. Can some one please help? One more question is my designation changed when i moved to new project under same employer. Is this considered as a material change? Can this be a reason behind the H1B amendment initiation?