Ways to maximise salary bonus?

Hi everyone, I work a job with an annual bonus that usually sits around the £5k to £7k mark. Last year was my first year working after graduating and I hadn’t really thought about it but I was completely slaughtered by tax, and I’ve heard it might be possible to put the entire bonus into a pension to preserve its value. I was wondering if anyone else has heard of this or if there are any other ways to keep more of it? Is this even a viable option?

Would it be worth putting half of it into pensions because I still wanna put them in an index fund/go on holiday with some of the money?