What does having TouchID on the iPhone have to do with the iPad? Having TouchID on the iPhone won't make getting into your iPad any easier. This one is really about your own habits.
To expand on what I mean, most people who use their iPads at home will unlock the device and then use it for a long period of time. Just to throw a made-up number out for the sake of example, they might unlock their iPad 2-6 times per day. The iPhone tends to be used in short bursts, and people check it multiple times per day (emails, text messages, among other things). They're probably unlocking their iPhone anywhere from 10-40 times per day. It's for this reason that a lot of people claim that they don't see a point of having TouchID on their iPads.
Your usage is unique to you, though. Are you going to be using your iPad in short bursts and/or locking/unlocking the device much more per day? If so, TouchID is worthwhile. If you're using your iPad for hours at a time and only seem to be unlocking it a few times each day then TouchID is still a nice feature, but the utility of it is somewhat wasted.
Granted, I've been discussing TouchID in the limits of iOS 7, where it can be used to unlock devices and make purchases from the App Store. iOS 8 will be opening TouchID up to developers, which might increase its utility. It's difficult to say for certain.
Regardless, my opinion - for my own usage - is that I'm content to continue using my outdated iPad 3 that lacks TouchID at home, but it's a must-have feature for the busy workplace where the iPad is switched on and off very frequently.
