Hi @iesmail!
The short answer is no, with some caveats 
A CHW having a paid for mobile bundle isn’t the same as being able send SMS via an API. Mobile providers have a different contract and different cost for API access.
The long answer is that the CHT has three primary ways of sending SMS for Magic Links as shown on our gateway docs page:
- RapidPro
- Africa’s talking
- CHT Gateway (deprecated, not advised)
Technically speaking, you might be able to set the CHT Gateway by having a physical mobile phone in an office with the CHW’s mobile bundle, presumably through a second SIM on the same bundle, and have the CHT use this to send SMS. However, you would need to have one phone/SIM combo per CHW and aside from being very fragile, simply wouldn’t scale.
If your app is Medic hosted, you can gain access to our hosted RapidPro instance. In addition to working with many SMS providoers, it can use data based services, such as Whatsapp, which may have a very low /no per message outbound cost. TextIt is the same offering as RapidPro, but is a cloud based commercial service instead of self hosted.
Should it be of help, Twilio has a non-profit division which offers $500 in credit and 25% discount for NGOs. Twilio itself supports SMS as well as data based protocols mentioned above. It is trivial to use Twilio with RapidPro/TextIt. Medic has done this integration before and would happy to assist should you want to pursue it!