I have a collection and a credit card with roughly the same balance. I received a bonus and I am able to pay off one of them completely. Which is more beneficial to pay off first?
I'm assuming you're in the US, answer will vary by country.
Even after your collection account is paid in full, it will remain on your credit report (for 7 years after it was initially 180 days late). The latest scoring systems FICO 9 and VantageScore 3 will not be impacted by $0 balance collection accounts. Older versions of each (still commonly used) didn't have this exclusion and your score could be impacted regardless of balance for the full 7 years of reporting.
On the other hand, a current high utilization rate is hurting your score, and costing you a fantastic amount of interest.
Which is more beneficial to pay off first?
The credit card is actively costing you interest (assuming ~$3,000 balance at 21% interest that's $52.50/month), while the damage from the collection activity has mostly been done. Pay off your credit card, get your budget in order and aggressively pay off the remaining collection balance next.
Utilization is a large part of your credit score (~30%), you might see a bigger bump in score from bringing utilization down (and keeping it down) than by bringing collection balance to $0. But even if paying the collection first did help your credit score more in the short-term, saving all that credit card interest will help you get on track financially.
The collection is taking free swings at your credit score the longer it stays around.
A credit card tends to take swings if you miss a payment or get close to your limit.
Your credit score will survive and even increase with a credit card in use (paying min on time) but this collection is killing / killed your credit score.
I'd pay off the collection while keeping up with min payments on the CC. I would also recommend keeping your CC at less than 90% capacity.