Without ferretting around for bank statements in David McVicar's bin, that's not an easy question to answer. Public money doesn't mean public information.
However the Royal Opera House's 2008-09 accounts provide a clue. Because Judith Weir and Mr Hytner are Trustees of the ROH, the accounts have to say how much they were paid.
So here goes:
"Judith Weir, a member of the Board of Trustess, is also a composer, and received a payment of £20,000 plus VAT during the period in relation to a commission for a new opera. Sir Nicholas Hytner is a member of the Board of Trustees and also a stage director. During the period he was paid £10,000 plus VAT in relation to directing a revival of Don Carlo, staged in September 2009."
Judith Weir's payment relates, presumably, to the recently-announced co-commission for Miss Fortune, to be shown at Covent Garden in March 2012. So it's fair to assume there are more payments to come. For the amount of work that goes into writing a score, I'd certainly hope so.
Because the ROH accounts cover the year to August 2009, and Don Carlo was shown in September, it's conceivable that Mr Hytner too received a top-up later. Though £10,000 should be enough to keep anyone going for a while, particularly if they have a full-time job to fall back on.