The following sites may help you know how to read the xml result of a webservice using vb and bind it to gridview:
http://www.aspdotnet-suresh.com/2012/05/aspnet-read-xml-node-values-and-bind.html
http://challlengebrains.blogspot.in/2011/05/how-to-bind-xml-file-to-gridview-using.html