Can a wildcard benefit from Inspiring Command on let's say...
V Ult Cap, by copying the ultimates TA? (as long as he is worth less than Cap of course)

The bolded part is the key. Some effects work with team ability (like Brilliant Tactician) but Inspiring Command requires you have the same printed team symbol.

So the short answer is no.

A wildcard could only benefit from Insp. Command if it were on a character with the same wildcard team symbol.