Similar to Rinsky above! I'm bilingual and didn't get interviewed. Grew up speaking both English and French at home, attended fully French and French immersion schools and then an English-speaking university, have held jobs in both fully English and fully French environments, etc.
In terms of EC's, I've held multiple leadership positions in different organizations/campus groups throughout undergrad and usually balanced 2-3 part-time jobs. Got a few awards/scholarships (related to academics and community involvement) and conducted an independent research project in my final year. Nothing that really stands out, honestly. My referees did know me quite well though, both from class and different EC's - which I assume led to stronger letters. Not sure it matters, but I spent considerably more effort on the PS for McGill than the other schools I applied to.