How do math PhD admission committees view reading courses when your university doesn't offer graduate classes?
Admissions committees in math departments know that a "small liberal arts college most people haven't heard of" might not offer the sort of advanced math courses that are available elsewhere.  If your REUs and Math in Moscow lead to strong letters of recommendation, you should be OK.  I'd suggest that you also get a letter from one (or maybe more) of the professors who are supervising your reading courses.  Even if (s)he has to write before the reading course ends, it would be good for the admissions committee to have some idea of the level of the course (e.g., what book(s) are you reading) and how well you're doing.