Well, I've only played Interpoker (which many don't cosider a very whoreable Cryptologic site), but
their page on the month bonus is pretty clear:
[ QUOTE ]
Which hands count towards clearing my bonus?
Every time you’re involved in a hand on any table (even if you fold before the flop) where a rake of 0.25 units ($/£/€) is taken (the equivalent of a 5 unit pot) the hand will counted towards your bonus.
[/ QUOTE ]
Please note that other Cryptologic sites specifically set a hard bottom limit, like $1/2. You MUST check the rules forthe site you're playing (and don't put your money on random replies in threads like these, unless they link their source. I'm amazed how many are shamelessly wrong. )
Note that, as strange as it may sound, you need to pay a higher rake to get a qualifying hand in pounds or Euros than US$. Several other Cryptologics have similar policies in other regards -- e.g. $3/6 might qualify for some promotion, but £2/4 won't, even though £2 >$3 (Those are not the actual levels at which the problem occured, but I don't recall the denominations of the £ tables, or the game involved)
Table/Game selection can help you achieve decent rake rates at quite low stakes, if you can play well in those conditions (if not -- learn!) I've been in $.25/.50 Limit Omaha games where 80-90% of hands reached $.25 rake ($5 pot). (During typical US playing hours, few Omaha tables are in play, so you play whatever is open.)