I have called up Tricor the registrar of Homeritz on Friday morning. The WB warrant price, exercise price, and number of warrant all will be adjusted after the mother share's bonus issue.

The number of WB warrant will be multiply by 1.25 (free WB warrant)
The WB price will be divided by 1.25 (RM 0.39/1.25 = RM 0.31, rounded)
The exercise price will be divided by 1.25 (RM 0.54/1.25 = RM0.43, rounded)
The exercise ratio remain the same
Even after the bonus issue of the mother share, the existing value of the WB warrant remains unchanged after the adjustment above. So it doesnt matter if you buy before or after the bonus issue.

For example:

Situation 1: Before bonus issue

buy 10,000 of Homeriz-WB = RM 0.39
Mother share price = RM 1.03
Exercise value = RM 0.54
Exercise ratio = 1:1
Premium: RM -0.10

If you convert all the warrants before bonus issue, it will be:
10,000 x RM 0.54 = RM 5400 for conversion
Cost of warrant: 10,000 x RM0.39 = RM3,900
Total cost = RM9,300 to get 10,000 of mother share worth RM 10300. Profit RM 1,000
The potential fair value gain for this warrant WB is RM 0.10/RM 0.39 = 25.64%


Situation 2: After bonus issue:

If you hold the warrant until the bonus share, it will be:
10,000 existing warrants + bonus 2,500 WB warrant = 12,500 warrants
New WB price = RM 0.31
New adjusted exercise value: RM 0.43
New mother share's price = RM 1.03/1.25 = RM 0.82(rounded)
Premium: -RM0.08
Cost of conversion: RM 0.43 x 12,500 = RM 5375
Value of 12,500 mother's share = RM 10,250
Profit: RM 10,250 - RM3,900(warrant cost price) - RM 5,375- (conversion cost) = RM 975
Potential fair value gain is RM 0.08/RM0.31 = 25.8%


CONCLUSION:
The fair value gain of the warrant are the same, regardless you buy it before or after bonus issue.
Slightly higher return after bonus issue due to rounding up effect of exercise price and mother share's price.

My advice is HUGE BUY since it is trading at 10.8% discount to mother's price.