In App Billing support multiple accounts reported as a bug in code.google, have a look at it
According to Mr.Sergej (posted in G+ android dev community) in-app products purchased with the first account won't be active anymore while using multiple user accounts!.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…