No simple solution

Whether remote workers are likely to encounter promotion-related bias depends on the organisation's working model. 

If you're in the minority of people who are working remotely, you're probably at a disadvantage in terms of promotions. But if the majority of people in the organisation are working remotely, then it will be a different story.

Policies are relatively new, and it's unclear to what extent they might close the promotion gap between remote and office workers, but achieving parity will be a long process.