You're definitely about to be laid off in exactly 4 months.
There is a chance you'll also receive a modest severance package at that time, but it's probably not worth the risk of getting dumped on the street and having a period of unemployment. It's a LOT easier to get a job when you have a job, and unemployment is LOW right now, so you might have enough leverage to get a salary bump higher than what the retention bonus was worth. There are zero reasons to sit around and see what happens.
Start looking now. If you've neglected networking so far, you have 4 months to join a trade organization, polish your LinkedIn, talk to recruiters, etc.
I also suspect we are going to have a recession soon (if not now) so unemployment could be higher in the future. It's not worth the risk to wait.
At this point early in the game, I would talk to a couple of industry recruiters. Tell them you need a salary that is your salary plus 15% and that you're not willing to travel more than X miles from your home. They are utterly desperate for warm bodies, so if a qualified person like yourself walks in they are likely to drop everything. Complete idiots are doubling their pay in this environment, so the timing is perfect. Seize the moment.