Follow what Silver Creek has said & you'll be fine. Diameter is a far better indication of what to use than the "X" designations.
I used to get confused too about all the "X" designations. Fact is, different makers may have different formulas for their material & breaking strengths are often averages of their testing. So, when comparing different brands it's not always apples to apples. It's also in their best interest to inflate the "averages" a bit to make the tippet seem stronger. After all, why wouldn't an angler want the strongest tippet with the smallest diameter? What's on the label may or may not be a true measure of actual breaking strength in real life fishing situations. Sometimes even the labelled diameter may not be accurate if you check it with a tippet gauge or micrometer.
I remember some magazine articles that compared various "tippet" & some that compared various bulk line & it was surprising that much of the results didn't match the labeled measurements.
Since you're fishing for panfish & bass, it's not going to be critical what diameter tippet you use. As long as you use a tippet that strong enough to handle the fish & conditions, you should be good. Keep in mind too that the type of fly you use may work better with different line diameters to get the best "action" from the fly.
Silver has also posted some great information in the past about why to use certain tippets & materials for "drag free drift". However, that primarily pertains to dry flies, and may not be something to be concerned with for panfish or bass. If it is, then the same line of thought can be applied.
I stopped using "tippet" material long ago, since I'm primarily a warmwater & tidalwater angler. I simply buy bulk spools of line, which is often less pricey than tippet. I also tie my own leaders, but do follow what Silver Creek has posted to get efficient transfer of energy. That's the important part of leader & tippet construction!
Heck, I make my leaders & tippet with Yozuri Hybrid, which I also use on some of my baitcasters & spinning gear, & most of the time I'm simply using 20 lb test for tippet anyway as I'm targeting bass in some nasty snags or Striped Bass & that size tippet stands up to the abuse better. The fish don't seem to mind!
When I'm fishing for panfish, I never get concerned about "X" labels & anything from 4 to 10 lb line for tippet is fine!