I've been wondering cause in the rule book does not explain about it. We always played that , yes, it can improve a Space Dock production since its based on the value of the planet ressource + space dock capacity+enviro compasator. Since the planet with a rafinery is now at +1 ressource, it would be logical to count it also as a +1 unit produced since the math for production is PLanet ressource+space dock. And what i think also is that this is the purpose of them since it can improve the production capacity of a player who would have low ressource systems or just to maximize the production of a high ressource system or one of those 2 triple planet hexes. And they can be built in the same time of a space dock....so spending 5 ressource for space dock+rafinery is imo a very good investment(be sure to cover it with enough GF...because yeah Local UNrest sux). So if ppl arent sure about using em...well its not something ill built every turn but yeah it surely helps to catch the ppl with massive ressource territory. So just let me know if im in the good way of thinking.

As far as I know, you are correct. A refinery increases the base planet's resource value by 1 for all purposes.