Grrr, now had a reply (via my TA), saying that the benefits cannot be applied 'retrospectively', so that I have 'Major' status now - but can't have the benefits on my forthcoming cruise (15th Oct), as they can only be applied to 'new bookings only'. They seem to apply this scheme very inconsistently!
I also had repeated emails (before and after my first booking), saying that there was an EUR500 discount for all new bookings. I am a UK customer and they are aware of this but the discount applied to my booking was £200! I pointed out that GBP/EUR has NEVER been 2.50 - but was told this was 'nothing to do with the exchange rate, it just IS £200' (!)...not a fortune, but irritating!