When you bled it the stat hadn't probably opened hence the heater is not
blowing hot as its only got air in it.
Try bleeding it for longer, run engine with rad cap off and heater off, get it up to temp
and top up the rad as you go, turn heater on max hot, if its not blowing hot try raising
the rpm of the engine to 2000 which will help raise the coolant temp to open the stat,
when this happens the level in the rad will drop so top up and check heater is hot, job done.
No need to jack up the car when doing this, i've bled up plenty of mkivs and all done on level
ground, some are stubborn and need the rpm raised for a while to open the stat.
For what they cost i would fit new stat and cap but i'd check the old stat just to know if it was
working correctly or not.