tethering is included with Total Internet. There are even instructions on how to set up "Personal Mobile Hotspots" right on the Total Internet page.
Don't forget to count the free PVR service and the 2 free STBs in your calculations if you have MTS TV.
Bonus: A special offer just for Total Internet customers
As an MTS Ultimate TV customer you already have 1 wired set-top box rental included with your service. When you add Total Internet, you also receive 2 additional wired set-top box rentals and Whole Home PVR Service free. A current value of up to $12.00 a month.