Anyone who commits the luring offence could be charged. If it's a young offender, and they meet the specified circumstances of the offence, they could be charged. In fact, the research I referred to from the United States showed that of the youth who were targeted through sexual solicitation, one in four were targeted by peers--contemporaries, those of the same age. It's a possibility. I'm not aware of a case that's been reported in which a young person has been charged in Canada.
On the second point, you're correct: section 172.1 applies to the use of a computer system for the purpose of communicating with a child for that purpose, but that computer system has a definition in the Criminal Code, and it would not include a telephone. The substantive offence of section 152, for example, an invitation to sexual touching, would apply in a situation where a person invites another person to engage in prohibited sexual conduct. A case could be made using that in the old-fashioned way, as in the way offenders, before there were new technologies, used to lure a young person into their home or away from their parents' control for those purposes.