are these accounts linked?

The one you use via Verizon is a partner account. The two accounts are not linked and can't be.

There have been cases where someone leaves Verizon and then have lost access to their Y! Answers account and the Y! Answers team have been able to help them, but as you continue to be able to login directly to Y! via yahoo.com it's unlikely they will try to link the original account with your new Verizon one.

So it's best simply to use another browser which is not logged into your Verizon account and use that for your Y! Answers account.

Yahoo is Yahoo. We have to have a Yahoo e-mail account to participate. Verizon is a separate company, where you need an email account to use their services too. Verizon has a Q & A board now too? I didn't know that (nor do I like Verizon enough to care, even if I am their customer for some stuff. lol)

What you're asking is equivalent to "I bought some bananas, so why isn't money taken off for how much I still owe on my car?" The two are completely unrelated.

what is verizon net?

you can't transfer one lot of point to another account, that would be cheating.