Yourfavouritewines (formerly Gondola) currently have Rosemount Founders Selection Shiraz and Chardonnay for £4.49 a bottle.
This in itself is an average price for this quality of wine but with the use of the code WDOFFER you can get £40 off any order over £99. This brings the price per bottle down to £3.11 if you order 24 delivered to your door by City Link.
I also got 10% from Quidco although the site says 8%. This makes the price £2.87 which is better than most supermarkets can offer. The Quidco cashback is a percentage of what you pay less the carriage and the VAT.