If you are focusing on literature written in another language in a Comparative Literature Department there is no way that your level of English has to be as strong as a student of English Literature. My guess is that the people suggesting otherwise are not actually comparative literature students, but English Literature students.
It seems this may come as a newsflash to some people, but not all courses offered at American universities are offered in English. French departments offer courses ON French literature IN French. (or German, Italian, Turkish, Japanese). Students read French literature, discuss the literature in French and then they write essays about the literature...IN FRENCH! (or German, Italian, Turkish or Japanese)
Here is a quote from the Harvard University Comparative Literature Department webpage. I chose this department at random and I assume that it's, like, a decent department:
We do not have a single foreign language requirement but we do pay careful attention in evaluating prospective applicants to make sure that they would be able to satisfy our program requirements in a reasonable span of time. Our program requires declaring four languages, with coursework in three of them (one of which may be English). Most students we admit have a solid grounding in one literature and language and have had exposure to another (or more).
http://www.fas.harvard.edu/~complit/admis_qna.htm
Please note the bracketed phrase "ONE OF WHICH MAY BE ENGLISH." It is not even a requirement, and certainly not at the time that a student enters the department. If Student A is a native speaker of English, Reads well in Spanish, and studies Korean from scratch, Student B could come in with Fluent Spanish and Italian and study to improve English.
In regards to the following statement:
Consider this from the Comparative Literature at Binghampton Univeristy (they have a specialist in Turkish Literature as google informed me):
International students whose native language is not English, and have not received a degree in the United States, are required to submit Test of English as a Foreign Language (TOEFL) scores. The minimum TOEFL score for admission to the Department of Comparative Literature is 30.
http://www2.binghamton.edu/comparative- ... index.html
I don't know here, but it kind of looks like they take the TOEFL test a bit seriously.
Some of this stuff probably depends on the individual school and department, but the categorical statement that comparative literature departments require English language abilities equal to English literature departments is absolutely not true.
It has already been pointed out on this thread that nimhicaz's level of WRITTEN ENGLISH is probably higher than the linguistic ability of most comparative literature students in the literature that they study.