You're only adding the listener to the billTotal EditText so your method will only be called after you've editing the text in that field. You should put the watcher code into a new variable and assign it as the text change listener for both EditText fields like so:
TextWatcher textWatcher = new TextWatcher() {
@Override public void afterTextChanged(Editable s) {
enablecalifready();
}
@Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { }
@Override public void onTextChanged(CharSequence s, int start, int count,int after) { }
}
numofpep.addTextChangedListener(textWatcher);
billtotal.addTextChangedListener(textWatcher);
Also think about approaching enabling the button the way Robin says as they are right - it is cleaner