Trading question and Guild traders

Hey community,

When a guild has a trading post in a city, is that different than a guild member (myself) listing an item in the guild store at a bank?

I got lucky last night and found two large, sturdy, purple paintings. These are of no use to me. No one replied to my public chats so I listed them in guild store in the bank. ...then I saw a guild post that we have a town trader. Was I supposed to go to THAT trading post and list the item there?

Thanks