Yesterday we covered Virgin Atlantic's limited-time Tier Point promotion, which can get the lead booker to Silver (or even Gold) from a single holiday booking. You can read that one here . Turns out the timing wasn't a coincidence, because both British Airways Holidays and American Express have now jumped in with their own spring offers. Here's what's available to you. British Airways Holidays: 10,000 bonus Avios offer You can collect 10,000 bonus Avios when you book a packa