I decided to create an account because I was in a similar situation last year. Back in January 2017, I decided to switch to English and apply for M.A. programs after receiving my bachelor's in philosophy. I ended up applying to five English M.A. programs and have so far received three funded acceptances. In two cases, I was also selected for fellowships and one of the programs even told me I was the adcom's top choice. Admittedly, I pursued literature instead of rhet comp, but it is definitely possible to switch departments from philosophy to English.
I would start by looking at programs that are a strong fit for the kind of research you want to do and then check their requirements. Some programs stipulate you have to have a certain amount of English credits to apply. Unless you minored in English, it is unlikely you will qualify for those. Others want to see undergraduate coursework in "cognate" fields. Based on my experience, many, if not most, English departments consider philosophy to be such a field.
In a few cases, I also reached out to graduate advisors and I even had my academic history vetted by a few directors of graduate studies . In the end, I found plenty of programs that not only had professors I could work with, but also had no issues with my philosophy degree.
Trust me when I say they are out there. You just have to find them.