A couple things we tell people to try: try hiding it in chunky peanut butter, since it's harder to tell between a pill and a peanut. Also, soft treats (Pill Pockets are good) wrapped around it, cheese wiz, bread, or lunch meat are options. I don't think Tramadol has much of a flavor, so the yogurt thing might work. There are some meds that you absolutely couldn't do that with because they taste so nasty.
Another trick is to have at least 3-4 pieces that look identical, except only one has the pill in it. Give him one or two without, then the one with, then immediately give the next one before he's even done with the pill one. That way he's thinking about the next treat he sees coming, rather than thinking about what's in his mouth.
He's a cutie! I'm glad the Tramadol is working for him.