I have successfully registered a number with WhatsApp using Yowsup CLI like so:
Get the SMS:
python yowsup-cli registration --phone xxxxxxxxxxx --cc 1 -r sms
Register after getting the code:
python yowsup-cli registration --register xxx-xxx --phone xxxxxxxxxxx --cc 1
However, by doing so, it looks like it un-verifies the number from my phone.
Based on this link, it seems like there is a restriction on the WhatsApp side: https://www.whatsapp.com/faq/en/general/21009863
Is there a way to associate a phone number in WhatsApp with Yowsup as well as a mobile device?
Whatsapp only has a single-session thing. You won't have any way to do it.