Use tabular numerals for phone numbers?

I realised it would be possible to use different numeral sets for phone numbers (and possibly other things) in certain context. For example, in a paragraph you might want a phone number with old-style numerals:

But in most other situations you’d probably prefer tabular numerals:

I’m undecided if this within the scope of this reset. Probably my biggest deterrent is that it would use a less-than-popular selector:

a[href^="tel:"] {
  font-feature-settings: "tnum" 1, "pnum" 1, "kern" 1; /* Etc. */
}

This particular feature might be better saved for a “Going beyond Normalize-OpenType.css” set of examples, which could include the features you need to have an opinion on to use, like stylistic sets. I’m pretty open to opinions on it.