'Today the UK Border Agency announced that these plans will be implemented from 29 November 2010. From this date, any migrant who wants to enter or remain in the UK as the partner of a
British citizen or a person settled here will need to show that they can speak and understand English, by taking an English language test with one of our approved test providers.'
Tier 1 and tier 2 visa holders are neither British citizens or persons settled.
Settled status
You are normally resident in the United Kingdom with no immigration restriction on the length of your stay. To be free of immigration restriction you must have the right of abode or indefinite leave to enter or remain in the United Kingdom.
http://www.ukba.homeoffice.gov.uk/glossary?letter=S