The only time I tell Ozzy bed is when we are literally going to bed ourselves and he understands that he is to go to sleep now.

It seldom needs said as he loves his kip and often slopes off hours before we do and ligs it snoring away on his beanbag (and glares when you knock the light on if you need a cuppa!)

I know I'm going to get shot down for this, but I do tell Takara to get on her bed when I tell her off.

I usually use it to say 'out of the way' while we're eating, or if she's getting under my feet, but she doesn't usually do anything that she needs telling off for. If she snaps at Eddy when he's eating, she gets told 'on your bed' and is told to stay there until he's finished but thats because he won't eat otherwise and the bed is the only comfortable place for her to sit in our flagstone kitchen.
Also, if she is getting hyped up and starts barking and biting (usually at my dad as he encourages it...) she gets told 'on your bed' to calm down. Usually though, she doesn't need telling.

just to add - she still loves her bed big time! I never say it in a negative tone, but do tell her to get on it.

At bedtime I say 'bedtime, on your bed' and if they're in the way she understands 'excuse me' my family think it's hilarious!

When Jake and Charlie are getting a bit too rough with eachother playfighting.. I tell em to "Chill" and they each take a sofa each and lay down for a bit...

Ha ha same here, when I say move towards the bedroom Roxy is already curled up asleep on my pillows

She stays up there until we've finished reading and when the lights go out we say 'get down' and then she jumps off and lies on her bean bag.

And then we wake up to her back on the bed between us again

If she is pestering us at dinner time my OH will say something like 'go over there' or 'out' and she will generally go and curl up on the sofa till were finished.

This will sound odd and maybe confusing, i don't know how it works but it does!

The dogs sleep in the utility room, which has a baby gate on, with their bed in.

As a punishment they are told to "get in their bed" in a firm voice if they have been really bad, and when it is bed time or we want them out of the way we say bed time. The difference is when it is bed time they lay down on their bed, when they are being punished they sit at the gate giving us the sorry eyes. They dont go to their bed when they are punished they go to their room.

We understand it and they do but it is a tad confusing.

I know exactly what you mean - Takara sits on her bed if she's been told off, but lies down if she's comfortable and gone there by choice, or because it's bedtime or our dinnertime.

I never did say 'on your bed' because of the negative association thing, but my parents always said it to their dogs, so they did it with Takara, and it just seemed to work.

It's the control she has to have to stay there til I say 'finished' that is good for her I think.

I say 'get in your bed' for a variety of reasons. Their bed is actually the dog room, and the only time that we say this is usually when I don't need them under our feet in the lounge or living room. Or when we ourselves are retiring to bed.
I wouldn't believe it to be a punishment, more of a time out for both parties. The dogs know however that if its daylight and we say it, then either the hoover is coming out (whereby they go there instantly on hearing it) or we have visitors and they will come out to meet them soon, once we have determined the visitors temperaments towards our dogs. If its dark, then its time for sleep when they will retire to their individual beds.
The bed/room has never been used as punishment, and I do believe that it should be used for time out for the dog if they should so desire and visa versa.

I tell mine to "Go and lie down" but its not a punishment, its usually because they are under my feet!

At night when we are ready to go to bed, the boys are usually curled up on the sofa sleeping.

I say 'bedtime boys' and they instantly jump up wait to be let out for a wee then run back in and jump into their beds.

I think its the anticipation of the bedtime biscuit that they associate their beds with though at night!!