Resolved; Compatible with MageRewards 1.4.2+
The MageWorx SeoSuite Tag class collides with the MageRewards TBT_Rewards_Model_Tag class rewrite.
To resolve, simply either change TBT_Rewards_Model_Tag so that it extends the MageWorx version of the Tag model, or change the MageWorx SeoSuite module so that it extends TBT_Rewards_Model_Tag. Either way, you should also be advised that this change will bind both applications together and will not be included in any future updates of either application.
Please keep in mind that implementing any modifications to your MageRewards core code does void your support agreement because you're adding dependency to the other module.