I’m really surprised I get this question. I was asked 3 times and I figured I would write a short post on the answer.
YES.. Ok, now ‘why’ its yes..
You do NOT have to jailbreak you iPad to tether. You only have to jailbreak the iPhone. (if you are using an iphone that is) Keep in mind that the connecting device is the device that has the 3G or whatever wireless data transport. The iPad connects to your device using WIFI. So the iPad does not know (or care) if its connecting to a phone, a wireless router, or smoke signals as long as it follows the 802.11x protocol. So you have tethering working on your iphone already, then you are good to go with the iPad.
Hope this helps.