I think that only the 1975-1977 lineup could be considered "Wings". Jimmy and Denny both contributed songs to Venus and Mars/Speed of Sound and were featured during the world tour.
Here's an excerpt from a January 1975 interview Jimmy did with Guitar Magazine.
Is your contribution going to change the nature of Wings?
I think so. Wings wasn't a band before. It was Paul with session musicians. Now it feels like a band, and I'm able to say my own things and voice an opinion. I can say, Listen, why don't we do this? If it works, we do it. It's everybody being able to speak up and contribute, even though Paul is so dominate. He's a very together guy as far as arrangements go.
Which is the more important aspect of Wings' work at the moment, live gigs or recording?
At the moment, records. It's a challenge at the moment because, apart from the single, nobody knows what the new band sounds like on record. So the first thing is to get a new album together and see how that works out, whether people accept it. We've already got most of the Band on the Run album together as a stage act, so we know we're capable of doing that. Now we want to go a bit further. I think the band will change, because before there was only Paul, Linda and Denny influencing the music, now he's got a drummer and a guitarist.