No, it is not possible to boost your campaign at any point during its promotion.
Your campaign will run for 14 days with the settings that you originally selected. There is no way to make any changes.
If you want your campaign to run with a higher budget and hence to reach a broader audience and playlist curators, you will have two options:
1) re-launching your campaign once it finishes;
2) setting up a new campaign when your campaign ends.