都是對的!
用be familiar with 表示“主語熟悉with 的賓語”
用be familar to 表示主語被to賓語所熟悉
即：
Sb is familiar with sth
Sth is familiar to sb
如：
這首歌曲我熟悉
The song is familiar to me.
=I am familiar with the song.