不是啊,是宾语从句.that you love me 是tell 的直接宾语.tell sb sth.
同位语从句与宾语从句区别很明显...
宾语从句是在没有宾语的前提下,加上关系副词,充当句子的宾语成分．
同位语从句是在名词后加上关系副词的,作进一步解释或叙述．
就如你下面的那个句子：
I heard the news (that a new student would join our class)
I heard the news 已经成句,that后面的内容只是把news详细点说出来.所以是同位语从句.
再比如：
News came that Bush was criticized by his assistant.
News came 已经独立成句,而后面是补充说明News的 ,同位语从句.
I wanted to tell you that Bush was criticized by his assistant.
I wanted to tell you sth. tell要求双宾语,所以缺一个宾语呀,that ...就充当宾语 ,宾语从句.