Is there a particular time of the year that credit cards give better sign up bonuses?

No. But these days, we don't sign up direct with the bank anymore.

We Sign up via:

1. Singsaver

2. Moneysmart

3. Gobear

They work with the bank, take a commission for gaining new cc sign up, with that they give applicants a cut via groceries or shopping voucher or lucky draw (Gobear).
They are legit. Why go with these ?

1. The extra voucher you get with them and

2. You can get also the bank sign up gift / bonuses

So stack up and get more! :)

P/S: When applying, remember to read and follow the instructions closely so nothings get lost in the process.

Happy stacking :P