When do you use "Anglophone", and when "English speaking"?

I only use the latter, because I operate under the axiom that my opposite has no idea what the former means, and believes I am talking about some sort of obscure musical instrument.

“Anglophone” is used for Academic writing or formal studies such as government papers.

“English speaking” is used in conversation and informal writing.

How about WASPs? Are they anglophones?

I ask because some people were debating that.