Which do you like better, tea or coffee?  

这里的 tea or coffee 是 which 的同位语吗？

The answer to your question is as follows：

(1)It is justified that you think of "tea or coffee" as the appositive of "which".

(2)It is justifiable that you see "tea or coffee" as the appositive of "which"

(3) It makes sense for you to interprete "tea or coffee" as the appositive of "which"