Principality Building Society will donate £50,000 to two Welsh charities thanks to Wales’ Grand Slam win at the Guinness Six Nations. Wales’ largest building society is donating a maximum of £50,000 to be split evenly between Alzheimer’s Society Cymru and Teenage Cancer Trust Cymru, after it pledged to donate £10,000 for every game Wales won. Julie-Ann Haines, Chief Customer Officer at Principality Building Society, said: “It was an unforgettable Six Nations tournament and as huge fans of rugby we were…