It shouldn't cause an issue. I have an iPhone and iPad, and I've got all of the tabs on all of them.
What does the iPad tab look like in iTunes right now?
Was the iPad hooked up to a different computer previously? (If so, it probably would have asked you to erase it or set it up as a restore from your iPhone)
Anything already on the iPad that you don't want to lose? (If not, I'd see what happens if you hit the restore button to wipe it and set it up from scratch again)
edited to mention the easiest solution if the sync service has stopped working on the iPad, try a reboot. Hold power button til the slider shows up, then slide, wait about 30 seconds or however long it takes til the spinner goes way, then turn it back on