LM, it's not a function of whether or not you're an
ebay member, but of the addresses the scammers have obtained from outside sources. They send out all sorts of phishing messages for all sorts of financial institutions in the hopes that the law of averages will match their spoofed message with an actual member of that institution. I belonged to an organization which sent out alerts on spoofed financial institutions and virtually every major bank and credit card company in North America has been spoofed. I've received phishings from Wells Fargo, Fleet Bank, and a host of others with which I have never had dealings. Most are to me using an alias address I use on public websites, but don't use for financial purposes; thus I know the messages are fake.
Consider yourself lucky that you haven't yet had
ebay phishing attempts. What this means is that you're not on the spoofers' email list... yet. But you will be; just be aware when you do get them that many/most messages other than expected online bills/statements are probably fraudulent.