We track the inflows separately in our DB:
subscription_rshares
delegation_rshares
curation_rshares (these are the rshares from upvoting rewards)
other_rshares (not currently used)

These are summed and the rshares already delivered are netted out to find the pending rshares value, which is the value the status calls delivers. What % of that balance comes from upvoting rewards is not readily available and an approximation would need to be calculated.

I plan to break things out and add something like 'xx% of your total upvotes received have been from upvoting bonuses' but we need to update the other_rshares column first to add in a couple of adjustments that were made. Right now the fields would not add up properly.

Which is to say it's all in my road-map, but we haven't started on it yet.