The Real Slim Shady
I think we are now getting into another area, namely ETOPS. I think the original question was 'is there a limit on distance to a destination alternate?' The answer under JAR, I believe, is no. BUT, ETOPS rules could come into it if there was no other suitable airfield within the non-ETOPS time/distance limit.
So you could logically deduct that there would be a limit if you would have to fly under ETOPS rules to reach the destination alternate and your a/c was not ETOPS capable. Equally though, I suppose you could deduce that you could fly absolutely miles away (why you would want to I don't know), if there were suitable en-route alternates that would allow you to get to the destination alternate non-ETOPS.
As for flying ETOPS to a destination and then flying ETOPS to the destination alternate, I would assume you would be getting into Isolated Airfield territory then, with different rules.
PP