There really isn't that much difference in ps to bhp. The mk3 GTI 16v is 150ps which is about 147bhp.
If the 1.4 was 100ps, that would make it about 98bhp which isn't right.
If you look on parkers.co.uk under reviews>technical data, you will see that all 1.4 mk3's are 60bhp which is about 60ps also.
1 PS = 0.98632 BHP