I would start by defining your problem more precisely. Which of the following would you consider a phone number that you want to match?
555-1212
310-555-1212
1-310-555-1212
(310) 555-1212
310.555.1212
+1 (310) 555-1212
310-555-1212, extension 1234
011 (46) 12-345678
1-800-MATTRES (leave off the last "S" for savings ;-)

etc. etc. It'll be much easier to devise a regex after you've figured out what it is you're actually looking for.