Heya, Bill. Since WikiTree doesn't accept or store any kind of raw DNA test data, the answer is a no about actual uploading. But the good news is that there is an easy way to make note of your Nebula/YFull results.
Starting the same way you did when entering your 23andMe test information, from the top-of-page main menu go to Add > DNA Test Information.
You'll see a heading that reads, "Current Test List." To the far right of that is a link titled, "Add New Test" (well, actually, "add new test").
Click that and you'll get the basic test info entry screen. From the pull-down menu that says, "Click here to select DNA test," you'll find what amount to catch-all options for: "Other auDNA," Other mtDNA," and "Other yDNA." These can be used as needed to enter test information for anything relevant that doesn't have a pre-formatted option like "23andMe" or "AncestryDNA."
Just be sure to click "Add Test" once you've finished.
For analytic services like YFull, I recommend using the "Optional space for additional information" to indicate particulars about the original test (e.g., "Analysis by YFull on data submitted from 30X whole genome sequencing performed by Nebula Genomics."). That helps make it clear the who/what/how of the test.