Bounty Rewards Increase by Torment?

There is never more than 1 of these materials in a cache for characters below level 70. Above that point the number of materials increases with higher difficulty levels.

• 3 Materials: Normal - Master
• 6 Materials: Torment 1 - Torment 6.
• 8 Materials: Torment 7 - Torment 9.
• 10 Materials: Torment 10.
• 12 Materials: Torment 11.
• 14 Materials: Torment 12.
• 16 Materials: Torment 13.

The game limits your cache mats (including bonus caches) to 1 when below level 70, regardless of difficulty.

Source 1, Source 2

For 2.4.2 (Season 7):

Source: http://d3resource.com/difficulties/

Here's the cache materials specifically (Reg + Bonus):

• Normal-Master: 2 + 1
• T1-T6: 3 + 3
• T7-T9: 4 + 4
• T10: 5 + 5
• T11: 6 + 6
• T12: 7 + 7
• T13: 8 + 8