JR pass with Tadami line

1. Can JR East Tohoku area pass or JR East Nagano Niigata area pass be used with Tadami line between Aizu-wakamatsu and Koide ?

2. Can JR East Nagano Niigata area pass be used between Niigata and Koide ?

Thank you,
Ton

1. Can JR East Tohoku area pass or JR East Nagano Niigata area pass be used with Tadami line between Aizu-wakamatsu and Koide ?

No, neither pass covers the entire line.

2. Can JR East Nagano Niigata area pass be used between Niigata and Koide ?

Yes.

Thanks Uji.

By the way, is the line fully recovered or still required a bus connection in between?

The Tadami Line was fully opened on October 1st.
(I saw it in a documentary earlier)
https://toyokeizai.net/articles/-/622606

By the way, I saw this program.
https://www.nhk.jp/p/fudoki/ts/X8R36PYLX3/episode/te/P5Q28NKPY2/

If you come during the operating period, you can use the Seishun 18 Kippu（Seishun juuhachi Kippu).
https://railway.jr-central.co.jp/tickets/youth18-ticket/

Check the timetable here.
https://tadami-line.jp/access/
Aizu-wakamatsu（会津若松）
Nishi-wakamatsu（西若松）
Aizu-kawaguchi（会津川口）
Tadami（只見）
Koide（小出）
arrival（着）
departure（発）

Thanks haro1210.

The information is very helpful.