I might be overlooking it, however i can't seem to get my messages (SMS and emails) to have multiple alerts when they come in. On the Curve is was a setting in profiles. I've managed to change my profiles and create new ones, i just didnt see any where to 'check' for repeated alerts.
The Tour has the same OS (4.7) as the Storm... the Storm doesn't have repeated alerts, so I'm assuming the Tour doesn't, either. The alert will only go off when you first receive the message.