If you follow the lower winding's dot connection, in both cases it goes to two diodes, one feeding the 0V output for positive half-cycles and one feeding the negative output for negative half-cycles, so the circuits are identical
If you are using a bridge rectifier instead of four diodes, both of these terminals will be marked AC and can be connected to either way round to the transformer secondary
Brian
If you are using a bridge rectifier instead of four diodes, both of these terminals will be marked AC and can be connected to either way round to the transformer secondary
Brian