Transfer from t-addr to z-addr and how to check z-addr is associated with which t-addr?

z_listaddresses list two z-addresses and when I check with z_getbalance both addresses have no balances.
z_gettotalbalance lists 1.00003450 balance.

zcash-cli listaddressgroupings lists two t-addresses both with balances that ends up to the total balance above.

In the user guide https://github.com/zcash/zcash/wiki/1.0-User-Guide I can see how to transfer funds between z-addresses.

Is it possible to transfer from t-addr to z-addr?
How can I see which z-addr is associated with which t-addr?

Yes of course. Just use z_sendmany.

They aren’t associated that way.