Yes the bridesmaids and groomsmen do give angpao. Even though the couple would give each of them a small token angpao too for helping out for the wedding, it means the bridesmaids and groomsmen would "earn back" a small portion of what they gave to the couple as angpao for the wedding.
are you asking if the bridesmaids/groomsmen should give bigger angpao, or are you asking if the bridal couple should give the bridesmaids/groomsmen a bigger token angpao back in return?
if you are asking about 'should the angpao from bridesmaid and groomsmen to the couple be bigger?'
Technically speaking, yes, the Bridesmaids and Groomsmen are generally pretty close to the bride/groom, so their angpao to the couple would be bigger BUT you have to bear in mind a few other considerations.
1) your BM/GM (bridesmaids/groomsmen) could have different financial circumstances, what if they only just started working, or in-between finding a new job?
2) if you as the couple, already kind of let your BMs and GMs pay for their other stuff like shoes/accessories, or other gatecrashing props and decorations, this is already coming out-of-pocket from the BMs and GMs, and not to mention, how about them taking grab/taxi to go to your house in early morning, or stay back late to help you on the actual day, or they took annual leave or afternoon leave on some days, to run errands for you, or they needed to attend your wedding rehearsal?
If you are a generous couple, you would REIMBURSE all or some of the costs that your BM/GMs incurred, like their props and decor, their taxi/grab fare at least. And it is also courtesy that the bride at least pays for the BM dresses, or at least give a cap budget to let them buy whatever dresses they like, maybe maximum $100 or $150 per bridesmaid or so. Unless you are very relaxed and chin-chye, you don't care what colour or what style of dresses your bridesmaids wear and you just let them wear whatever dress they already have in their wardrobe.
However, this is not always the case. There are brides/grooms that just lets their BM/GM pay for everything by themselves.
So please ah, be more mindful of all the extra costs that your BM/GMs have already had to pay out-of-pocket.
There are generous couples, but then there are also selfish couples who may end up going overboard and exploiting all their jie mei and xiong dis (bridesmaids and groomsmen), expecting this and that.
There are generous bridesmaids and groomsmen too, who would go the extra mile and do whatever they can. But for couples getting married, please do not take the kindness, help and time and effort for granted and do not exploit your bridesmaids/groomsmen. They are taking time out to help you, when they could have simply said sorry no, and used their time/effort on their own personal life or rest time.
If you're kind and generous enough, you should offer to pay all or partial amount of their props/decor/transportation costs, any dress/shoes, accessories cost (if you wanted to have same theme throughout), etc.
Your BM and GM will give you angpao, but it also means that depending how close you are to the BM and GM, and how much effort and what tasks they did for you on your pre-wedding day and your actual-wedding day, you need to give them a 'token ang pao' back in return.
It may not be a very big ang pao, but it is a token ang pao, to thank all your helpers for their help.