This depends on if the writer is actually talking about a real temple or if he/she is using the word "temple" for style.
If for style, it just means that it's an extremely important site of education of some type. However, I personally would've used "of learning" rather than "to learning".
You could use it for any extremely iconic place. For example, "MOMA is a temple of modern art." "Widener Library is a temple of/for learning."
However, if the writer was talking about a real temple, then it means "temple". A holy site for worship.