都是对的!
用be familiar with 表示“主语熟悉with 的宾语”
用be familar to 表示主语被to宾语所熟悉
即：
Sb is familiar with sth
Sth is familiar to sb
如：
这首歌曲我熟悉
The song is familiar to me.
=I am familiar with the song.