Renee Zellweger. Mike Marsland/WireImage Renée Zellweger’s beau, Ant Anstead, joined her at a party for Bridget Jones: Mad About the Boy in London. But first, Zellweger, 55, hit the pink carpet on Wednesday, January 29, for her big movie premiere at the Odeon Luxe theater, wearing a show-stopping fuschia gown with a strapless neckline and…