I'd do the R&S first not just for the knowledge, but because it's a better deal than any of the other tracks. $150 for ICND2 vs $250 for every other CCNA track.
For CWNA you can go straight w/o requested taking CWTS however, it is real dry to study.
For CCNA-W you have to take ICND1 first; which is a requested in order to take CCNA-W. You don't have to finish ICND2 if you decided going for wireless.
CCENT is a requirement for CCNA Wireless, and I think is sufficient. Probably if you want to go beyond CCNA W, then CCNA R+S is not a bad thing to have, both for the background knowledge and for hireability. I'm not sure what the market is like where you are, but in my part of the world senior (CCNP +) wireless engineers are usually also working with the other parts of the network to some degree.
Comments
Yes understanding the fundamentals is a must I believe
For CCNA-W you have to take ICND1 first; which is a requested in order to take CCNA-W. You don't have to finish ICND2 if you decided going for wireless.