Hi Tarik,
First of all, let me insist on the fact the a WAAS mobile client will not interact with a WAAS appliance on the core side and that you'll need to have a WAAS mobile installed there is you want your teleworkers to get the benefit from WAAS.
That said, let me answer your question: WAAS mobile can indeed accelerate HTTPS traffic.
This is described on page 61 of the following document:
http://www.cisco.com/en/US/docs/app_ntwk_services/waas/waas_mobile/v3.5/configuration/administration/g
uide/CiscoWAASMobileAdminGuide_3_5.pdf
Regards,
Nicolas