"Westminster" = central London, here used to refer to the center of English politics.
"Stephen Fry" = famous comedian
"be in a bubble" = be cut off from the rest of the world. In this case, it might refer to journalists who follow politics 24 hours a day; it might also refer to political advisors who read and write policy 24 hours a day. (Without more context, I'm not sure what "boys in the bubble" refers to.)
"be an answer to" = be an equivalent to; be similar to